Dead At 30K Miles!? Mazda Skyactiv-G 2.5 CX30 Core / Blown Engine Teardown

[@RainmanRaysRepairs]

I finally get to learn what Sky Active *really* means! It’s been a myth amongst us for years 🤣

[@dans_Learning_Curve]

Hey Ray! Good to see you!

[@dans_Learning_Curve]

Did you get your Subaru engine?

[@rumleyrum5839]

Yeah, now we know it isn't connected to Skynet so no baby Terminators coming from Mazda. At least not yet...

[@mybigfartsreallystin]

Rainman Ray in the hooooooooouse...

[@virtuosoification]

its ray ! hello ray !

[@Viper06290]

Mazda tech here. The Sky-Activ family of engines generally really reliable. In several years of being a tech at a dealer I can count how many full engines we have had to replace. Typical issues you will see with the 2.5L non-turbocharged engines will be a timing cover leak, but most often this will be covered under warranty. The 2.5L turbocharged engines occasionally get a cracked cylinder head, but these aren't too common. One thing to note about the Sky-Activ head gaskets, the head gaskets are stainless steel, and the heads or the block of the engine will usually fail before the head gasket does. They are easy cars to work on compared to most manufactures, and a great car for someone who would like to work on it themselves. They still do have transmission dipsticks (they are small, under the airbox), but its more than just about any other car manufacturer can say. Not really any specialty tools are needed for basic maintenance.

[@savagesam205]

I was amazed that my Mazda 2 DJ has a dipstick for the transmission. Many cars don’t even have dipsticks for the engine oil anymore.. My girlfriend has the latest 3 Sedan in Soul Red (my 2 is Dynamic blue). We both really like our Mazdas! They’re very reliable and enjoyable to drive.

[@lornestein7248]

I'm very interested in the 3.3t when the CX-70 comes out. Hoping it will be a long term winner!

[@karl_toffel]

Can you tell us something about the spinning thing in the camshaft?

[@therealebolaboy]

I owned a 2.5 turbo and it was a really nice engine. It ran perfect until I sold it, but I always wondered about intake deposit build up with the direct injection.

[@rudolphna54]

Dunno about that though, Car Wizard over on his channel just went through a head gasket replacement on a CX-9 with the 2.5L Ford derived engine and it was an absolute nightmare. Maybe that's just that specific engine.

[@CaptainTransit]

Since you said it was a rental car, here’s what I suspect: To start, rental companies don’t exactly take good care of their cars (speaking from experience as a former mechanic who used to service these vehicles). They will decline any repairs unless the issue actually hinders vehicle performance. They will decline an oil change unless the oil is practically darker than a black hole or the low oil pressure light comes on. So here’s my theory: The engine ran past the mileage its service was due. (My guess is 12k overdue) In turn, bad oil circulated throughout the engine (and gumming up cylinders 3+4), thus increasing friction. Increased friction equals increased heat. The increased heat stressed out and caused the head or block to warp and in turn, headgasket to leak externally, thus the loss of coolant. No coolant = overheat. Overheat = toasted engine. But other than that, Skyactiv is a tried and true technology if you take good care of it. My parents have a 2021 CX-9 and I have a 2024 CX-30, which we intend to run well over 300k. This is just a theory based on my experience servicing rental cars.

[@DroneStrike1776]

I remember getting a loaner when my car was in the shop, it was a new Acura TSX. I beat the snot out of it for the 4 days I had it.

[@thetechlibrarian]

I remember getting a brand new BMW as a rental for a 2-week vacation I was getting ready to go on down south I was about a day into my trip and realized the thing was overdue for an oil change I called him up seeing if maybe I could take it somewhere to get an oil change and they would knock a day off or something and they said no it'll be okay I just could not get over the feeling that I was ruining or significantly shortening the lifespan of this brand new car

[@MickyMouseLimited]

Very possible. I have Mazda 3 sky active the car is 2012 2L 12 to 1 compression all we do Is oil changes and I changed spark plugs once .

[@joshuaireland5510]

I've worked for a major rental company for over 3 years now, and while there is some truth to the abuse they go through, most people still end up driving like grandmas or however they would normally drive in an unfamiliar area. Maintenance schedules are longer than most would do for their own cars, but still follow 10k oil change intervals or less. Not the "best" practice but with modern full synthetic oils, engine wear is still a non-issue. Oil changes are tracked via the odometer and noted in the computer system (not by the annoying oil change messages in most modern cars that are hardly ever reset). Any vehicle that is due for an oil change cannot be rented, and if you try to rent a vehicle that is due for an oil change, the moment you enter the outgoing mileage, the computer with block it and you will be unable to assign the vehicle to a contract. That being said, other companies/locations may operate with much looser standards. There is also nothing stopping the average customer from popping the hood and screwing with anything in the bay. I've had older people check the oil on new cars, determine that it's low, then end up overfilling the vehicle with oil. I've also seen someone hold down the gas pedal while trying to start the car then complain that the car wouldn't start. On this mazda, I wonder if someone just straight up added water to the oil considering the headgasket still appeared intact 😂

[@evanb09]

If what you’re saying were true we’d see evidence of that. The rod bearings would be absolutely roasted and there would be varnish in the top end but they both look perfect. You don’t generate that much heat from lack of lubrication and not also destroy the bearings.

[@scooterwoodley195]

Been waiting for this one! I’m coming up on 400,000 miles on my 2015 Mazda 6 and I’ve never owned a more reliable car. Still runs and shifts great and still getting 33 mpg on the hwy. Beside a belt tensioner and an LCA, I’ve done nothing to this car except change the oil every 5K and drain and fill the transmission every 75K. I bought it used with 90K and it’s very comfortable and nimble. I will not hesitate to buy another one when it’s time.

[@onenikkione]

Is your 2015 direct injected like this one? The valves on this one already need to be cleaned from the carbon build-up.

[@Raptors0524]

400,000 miles? That’s unbelievable! I am hoping to get this many miles on my 2020 CX9. I just love this company!

[@scooterwoodley195]

@@onenikkione yes, mine is DI but I drive mostly hwy miles so I suspect that helps mitigate a lot of the severe build up. I was using CRC DI cleaner for a while but got out of the habit. Some day, I’ll probably zip off the intake and take a look. I will probably just manually clean them if they look built up. Would like to just do an EGR delete but probably not legal.

[@kurdokolenko]

my '14 mazda 3 skyactiv is at 500k km(300k miles) and it runs 10/10, no oil/coolant consumtion, rattles, noises, smoke etc issues. took the head cover and the intake just out of curiosity and they look exactly the same as the ones in this video with 10times less miles!

[@kevtn8]

@@scooterwoodley195 That's amazing. It sounds like you're averaging 40k miles a year ? My 2016 at 120k must be barely breaking in by your standards lol. Mazda recommends fuel injection cleaning every 30k miles. I've done it once. Otherwise I've done everything you've done for maintenance. It's amazing sedan for fwd.

[@coronelcool]

when a mechanic says this engines are hard to find you know that is good.

[@ivanvarela3215]

Hmm I would say the opposite. For my 2.0L mazda 3 2008, a good engine is $800 and I have hundreds to choose from here in BC, Canada alone.

[@Olemrac11]

@@ivanvarela3215 2008 is key here. thats when ford owned mazda in the western world. Mazda is a diffferent beast now

[@ivanvarela3215]

@@Olemrac11 a 2.0L engine for my mom's 2018 maxda 3 is only $1500. Not much has changed, they still have ongoing joint-ventures with various production facilities. Still a very easy car to work on, little has changed from the '08 model I have.

[@OSTKCabal]

@@ivanvarela3215 Except the entire architecture, the entire engine, the entire literally everything... yeah, totally, you're definitely right. Little has changed.

[@ivanvarela3215]

@@OSTKCabal one can still do all their general maintenance on their own, bud.

[@lgonzalez1154]

24 yr tech here and those engines are pretty much indestructible never torn one apart so thank you for the insight

[@VeritasAequitas01]

Hey sir, fast question for ya. Idle shake/vibration in 2.5 192 mazda 6 gj. 250k mil. Ac turned off and while its just on "p" i can feel like a one sec shake, its a moment and keeps repeating every 2 - 3 sec like missfiring but much less noticeable. However i do even think its showin up when engine gets warmer or its just me. Ppl says thats the mounts but its kinda pulsating vibes

[@BaeLasso]

@@VeritasAequitas01 I got a Mazda 2 with 270k kms on it, it has the same pulsating vibes you mentioned, I cleaned MAF sensor, throttle body, it got less shaky, and then I added fuel injector cleaner into the tank, after a tank of fuel, now the car is much much less shaky, though it still has that pulsation but barely noticeable. In conclusion I think it's just engine is old

[@VeritasAequitas01]

@@BaeLasso thx for reply sir. Tbh i stopped taking care of it cuz i have already chacked how those engine works in" fresh "cars...like cx5 2021 (around 20k miles ) and cx30 2020 around same milage. So i think its kinda normal. Just like u said maybe those throttle cleaning etc helps in some low % but its still shaky. Well the culture of those enignes seems lame idle working. I should already change the engine mounts also... Anyway till now almost 200k mil and no issues. Not even a singe failure in memory. Cheers bro!

[@ogopogo1397]

my dealer overfills oil by a half quart (1/8th inch over max bubble) and says dont worry about it. Manual says otherwise. What say you?

[@BaeLasso]

@@ogopogo1397 I say don't worry too. I have another new Skyctiv G Mazda, dealer always refill engine oil a bit higher than the max mark on the stick, it's okay, never has a problem... ~3mm is nothing

[@danven1256]

I was a Mazda master tech here in California, I retired a few years ago. I can remember getting a lot of bad mouthing from the Subaru guys telling me how crappy Mazdas are. The reality of it was our Subaru shop had at least six guys working on Subaru engines at any given moment while us Mazda guys did maybe one engine per month and sometimes less than that. We did have a rash of water pump belts that broke causing catastrophic failure but usually the failures I had witnessed were due to lack of maintenance. I have five Mazda vehicles including a 91 LE pickup that's as reliable as it was when it was new, the only thing I've had to do to it has been just maintenance.

[@yournightmare9999]

I have 100k in cx5 so now I have to replace timing belt, water pump, tensioner and anything else?

[@anthonyz7023]

I believe it has an internal timing chain. It has two drive belts.

[@redrum3835]

Yeah my 2018 Mazda3 2.5L with 150k miles had it's serpentine belt tensioner replaced roughly every 60k miles.

[@AzwanIdris]

@@redrum3835 how much it costs you?

[@davidread1133]

@@yournightmare9999😊

[@arvin6606]

Not an engineer nor have i teardown any engine. But i've seen many engine teardown and this is one of the simplest engine i've seen. No wonder why Mazda engine are so reliable. Simplicity is reliability.

[@finnyvindhalland9852]

The skyactive is not a simple construction. It is close to a diesel engine running on petrol. 14:1 Thats why it gets so high milage. This is an advanced invention.

[@TheSergio1021]

​@@finnyvindhalland9852 I think this is just semantics. Streamlined can be considered simple even if it took a lot of R&D

[@Tiberius_I]

Someday you will tear one down and that will be the fun one. About year 2000, Truck needed timing chain and valve job so I went ahead and did in-car overhaul to my 1988 Nissan Z-24 Pickup (w 180,000 miles) Honed the cylinders, (no ridge or anything), changed the piston rings. Left the bearings alone. I enjoyed doing it. When I had it all together, I cranked the engine and would not start! I thought for a second. Removed the distributor and put it 180 degrees from where it was. Engine immediately roared to life.

[@parafitality2730]

"No wonder why Mazda engine are so reliable" Not you rotaries (rip apex seals)

[@00wheelie00]

Sadly I once rendered roadside assistence to someone that had an overheated engine. He was confused as he had just refilled the coolant. After some asking it became clear he poured coolant into the oil. Could explain what you saw here.

[@MattGT35R]

As a long time Mazda driver (literally the past 13 years or so), I’ve been waiting for this. Thank you SO much!

[@akgonen60]

im alsot a long time mazda driver for almost 23 years lol love my mazda i got a 2021 mazda 3 hatch and a 2022 cx5 beautiful vehicles fun to drive

[@ironsales5669]

My wife and I just replaced our 2015 BMW 428i with the new 2024 CX-30 because the constant maintenance issues with the BMW and high cost of replacement parts. We bought the CX-30 for the very reasons outlined by others:, it is easier to work on, parts cost less, and this is a high quality car. I appreciate you putting out this video so I could see how this engine is put together. It does look easier to work on.

[@MagaTBTF]

Beemers Overpriced Garbage! Good move on your part! It does cost to say look at me I got a Beemer! All in all who cares right! 😅

[@AK-oz4ew]

We hape replaced 2021 BMW 430 with CX-30, and while insurance went down a lot, Mazda is a cheap rattlebox vs a modern BMW. Dashboard rattles dealer can't fix with long wait list to get a loaner, crappy infotainment software, noisy engine, jerky transmission, uncomfortable seats. Even rear space in a BMW coupe is more vs "5 seater SUV". The cars are two different leagues. Yeah, BMW is not as reliable, german engineering issues, expensive maintenance with ZF tranny, but with all of it Mazda is a cheap cost cutting box

[@Zachman676]

My mom bought a 2022 CX-5 with the 2.5 liter N/A Skyactiv-G motor and I have to say it’s a very nice little car to zip around in. Aside from the overall good aesthetics and build quality inside and out the drive train and handling are great. Not the most powerful engine but always willing to run and it’s probably one of the only cars in its class that doesn’t get out of shape when the roads turns curvy. Pretty fun package to take on a road trip. Overall satisfying vehicle purchase.

[@zbigniewbohdanowicz8897]

little car??

[@spamcan9208]

​@@zbigniewbohdanowicz8897While it's not technically a small car, it behaves like one. I have the 2018 CX5 and it handles extremely well. Even in snow Mazda lets your inner juvenile delinquent have fun and will let you kick the tail out (AWD version) before the stability system activates to bring it back in line.

[@zbigniewbohdanowicz8897]

I was surprised because in Europe it is considered a big car :) I have Mazda 3 sedan, and even this is not really small for me, just the right size

[@matsudakodo]

Agreed but the stock tires really hold it back. Put some good tires on and see what it can really do.

[@matsudakodo]

@@zbigniewbohdanowicz8897 here in the States it's one of the smaller SUV's you'll come across, aside from things like the Nissan Juke which I question the practicality of.

[@speed150mph]

As someone who isn’t a Mazda fan, I am very impressed by this engine. Some engineering team took their time to build a very good engine. Maybe I’ll have to consider Mazda when buying my next vehicle.

[@big0bad0brad]

Things got a LOT better once they kicked the Ford stuff to the curb

[@houtyfish273]

I previously drove Toyota, then Honda, and then switched to Mazda, I'm pretty sure you won't regret switching. They are phenomenal vehicles. My Toyotas I liked, but they weren't that great to drive, not terrible but just OK. The Hondas all had important things that really irked me all the time, like the ride / handling, steering and economy. The Mazdas: well the worst things about them are good, and the good things are amazing! We have a whole family of them (6 Skyactiv models in total) and have had zero problems! Even with my daughter's 2014 3GS, which has 200000 on the clock.

[@big0bad0brad]

@@houtyfish273 Yeah the worst complaints I can come up with against my '13 3 automatic are things like... the allowed RPM range for downshifting while keeping the transmission engaged is narrower than I'd like. Or the display tells me a tire is low but won't tell me which tire is low. I mean FFS if you're down to that kind of stuff you've got a good car.

[@houtyfish273]

@@big0bad0brad Exactly! When your only complaints are quite trivial..... Do you have the 2.5?

[@big0bad0brad]

@@houtyfish273 2.0L but I like to play some of the hypermiling games so it would have been my preference anyway. I found that buying the ecopia ep422 plus tires that the '14 came with were a big improvement over the factory turanzas in terms of not squealing like a banshee in tight corners and still maintaining efficiency and enough performance. If you trade the hassle of some downshifting and strategic air conditioner use, this car can be one of the cheapest to own; I haven't even done brake work at 198K miles because I haven't used them enough. But did have a wheel bearing go out but that kind of thing is a bit of a fluke.

[@boydgrandy5769]

You just sold me on this engine. With proper periodic maintenance, this is an extremely reliable setup.

[@BRB_GHONDi]

Have a first generation skyactiv Mazda 3 hatch, had it for 10 years at this point and it’s been impeccable. Driven 140k at this point with zero issues, definitely became a big Mazda fan over the years.

[@ctbale1]

Two issues. The rings are from the exh valve seals leaking oil, issue with the 21s. see TSB. And at 4:29 noon on the exh port the head is cracked. Possibly CD related. Coolant in oil. My guess is it got pulled for cyls 3 and 4 missfire from low compression.

[@HoytClagwell]

Congrats on the keen observation skills. 1800 comments and this is the only one I saw that noticed the crack. The crack appears to continue past the exh port on up the side of the head as well.

[@themikeroberts]

Good eye! Since you posted your comment, there's been a class action lawsuit settlement for the leaking exhaust valve seals. Mazda replaced them for free if you say your oil level has gone below the minimum on the dipstick in-between oil changes. How would the cylinder deactivation cause the crack? Uneven heating?

[@ag4allgood]

MX-5 owner of a 2016 & 2024 2.0 Liter Sky Activ engines. The 2016 never had a problem & was going strong when I sold it to get the 2024 MX-5. Really easy to work on these engines for the most part. Proven technology with variable cam timing. Mazda engineers shoved the engine to the back of the engine compartment so its almost a mid engine car giving it a 50 / 50 weight balance front to back with the driver in the seat. People think the Miata is just a weekend toy but my MX-5s do daily duty in 4 season weather. Keeping the stock height & using a set of dedicated winter tires turns this roadster into a great handling winter car. Really impressed by the quality.

[@iadr]

As a former dealer guy for ~6years, they have a incidence, low, but every dealer will see a couple, of porous/microcracking of head castings. 99.999% sure that is what happened here. MazdaTSB 01-013/21 Engineering of the SkyActiv family of engines is superb, as is, generally, quality control. Very premature drive belt failure is critical. Fortunately the water pump has its own belt, but AC and Alt belts never make 50K miles. Replace them before that or face a tow in.

[@ReviewingTech101]

😅 my 2016 Mazda 6 still has the original belts it has 135,000 miles all I’ve done is regular oil changes, brakes, spark plugs, transmission fluid it’s manual and replaced the coolant and 1 battery it still runs good 😊

[@ctbale1]

I think that tsb is for the turbo version. Too much weight on just six 8mm exhaust studs. Cracking around studs. The fix is the revised head and a different exhaust gasket

[@caseymuzio7609]

What was that drive off the front of the camshaft for it appeared to be geared to increase rpm

[@ReviewingTech101]

@@caseymuzio7609 i think it controls the timing, my car has something attached to it with a connector

[@larryaugsburger8452]

@@ReviewingTech101 I replaced belts at 100K and they looked brand new- no cracking or anything.

[@muskaos]

Mazda as a company has remained committed to the ICE, they have not gone EV. They have really pushed ICE technology to get good performance and emissions. I still drive a 2002 Protege 5 I bought new off the lot, 162k miles and still ticking. I'll drive a Mazda for the rest of my life.

[@Givelasagna]

I have a 2004 mazda 3 2.3l with about 143k. Still as strong as the day I got in 2011

[@jacksons1010]

Not true! Mazda already has an EV SUV on sale and more coming. Every manufacturer on the planet knows they need to offer EV’s or go the way of the dinosaurs.

[@PresidentSkroob12345]

Well... Mazda doesn't really have a choice. They don't have the resources like Honda or Toyota to invest in hybrid architectures, much less full electrics. That's why they're pushing internal combustion as far as they can.

[@markanderson350]

I bought my first Mazda in 2010, a 5. No problems yet at 210000. Miles. The transmission fluid had to be changes and oil of course. I did have a plastic part break for water distribution on the block. That could cause an overheat fir sure

[@jamesmedina2062]

@@Givelasagna Your vehicle was almost 100% made in Japan

[@shauncollins2017]

My first car was my grandfathers 1986 Mazda 626 with a 5spd manual. He bought it brand new and rarely drove it. We inhereted it when he passed away in 2001 and it only had 18,000 miles on it. Loved that thing!

[@Chris_de_S]

We had an 85 Mazda - is was garbage. They are slowly catching up to Honda and Toyota.

[@W0RLDSSMALLESTVI0LIN]

​@@Chris_de_S Mazda is actually more reliable than Honda now. Mazda is right behind Toyota in reliability rankings.

[@potatopotato8360]

It's so weird to think that in 2001, 1986 was only 15 years ago.

[@frasercrone3838]

A relative of mine here in Australia had his fail in a similar manner and it came from the crankcase venting system failing partially open and as the engine works as a partial diesel the crankcase has more blow by than lower compression engines. The oil mist being fed into the inlet manifold led to carboned up piston rings and engine failure through overheat. The inlet ports on your engine all looked wet with oil. I don't know where the crankcase breather feeds into the engine but maybe it favors 3 and 4 cylinders. This same problem was found on quite a few of the first series of four cylinder high revving turbocharged direct injection diesel pick up engines around 2009 to 2013 here before manufacturers got on top of it.

[@Vacman0331]

Steve from near Tampa, Florida here. I watch your videos and it reminds me of the days back in the 80s when I worked at a shop pulling engines from cars, tearing the engine down, sending the block out to be bored and honed, then I would rebuild the motor after all new pistons, rings, timing chain, gears, lifters pushrods and an in house job on the heads was done. Recently I have become a fan of the 2GR-FE engine and want one that I can rebuild.

[@DavidGarcia-oi5nt]

So much more respect to this guy after he named all the cool Mazda's he's owned

[@AnBarofSoap]

Nice name

[@InexplicableBill]

@@AnBarofSoap Would the real David Garcia please stand up. Oh wait...

[@ag4allgood]

He has owned & driven many of the coolest Mazda's - Miata / RX7 / 626 / 929 / Milenia / B series trucks ......

[@tbyron]

I have a 2.0 in my 2016 Mazda3. It was perfect at 110k miles, until a Mazda dealer Tech forgot to put oil back into my engine. They replaced it, no charge, but talk about oil starvation.

[@sebascc007]

Have a 2013 Mazda 3 with the 2.0 skyactiv engine. I think Is one of the best engines in the market. It Is responsive, Easy yo work on and reliable af. Mine has 164k on it and still going strong. I recently replace the Valve cover gasket, and inside that engine looks as good as this one.

[@onenikkione]

Have you taken your intake manifold off and looked at your valves for carbon? This one with 30k had carbon and if still ran should have the carbon removed.

[@sebascc007]

@@onenikkione the last Time the mechanic checked, told me it didn't need cleening. I'm planning to do it as preventive maintenance in the next maitenance

[@Kevin-hp5fk]

No surprise that a company run by engineers builds a great engine. I've had 3's with the 2l and the 2.5l NA Skyactiv-G's and they were both bulletproof. Easy to maintain, never missed a beat, and always beat the fuel economy ratings. Mazda builds some of the best cars and engines out there, and definitely the best at their price point.

[@Sprier]

I would have to agree these 2.5 skyactive engines are one of the better 4 cylinder options since the late 2010s. No oil burn great fuel economy and a decent amount of power for a lightweight economic chassis. Love the 2.5SA in my 3 with the 6 speed auto. Car feels very complete. 30+mpg with a heavy foot and sGT trim additional weight, best car I've owned in terms of being a "good car".

[@Lofi.z34]

How much bhp does the engine make?

[@Sprier]

@@Lofi.z34 believe it's rated at 184hp and 184tq, around there. The 2.0s are around 155/148

[@owenhollis5758]

​@@Lofi.z34 they make 190ish ps mx-5 makes 184 not sure what the rest of the American market gets tho

[@EnhancedNightmare]

Sadly the 2.0 versions we get here in Europe are a little bit anemic. Especially with automatic transmission.

[@LiborKroupa]

​@@EnhancedNightmareyeah. I have the e 186x 2liter or whatever they are calling it, six speed. Great car, unbelievable handling. But feels like it has half the horsepower...

[@robinpage2730]

Could be a manufacture defect: head bolt wasn't tightened enough, causing the coolant leak. You'd have to check the head and deck flatness both to know if the head or block are warped.

[@iadr]

No. TSB's have been flying out of head office to the dealers for a couple years now about porous head castings. Bolt Torque is not a factor. If it *appears* to be it's because the cracking let the head deform.

[@ccrider8483]

I was hoping that he would put a straight edge on the head to check for any warping. I have heard these newer aluminum engines are prone to warping if overheated.

[@ccrider8483]

I was hoping that he would put a straight edge on the head to check for any warping. I have heard these newer aluminum engines are prone to warping if overheated.

[@Slaktrax]

@@ccrider8483 Any alloy head is.

[@Mis73rRand0m]

Even iron heads are capable of warping; they're just more likely to crack first in an overheat situation. I was thinking porous material when I saw that strange exterior coolant leak in the video; there is usually a channel carved on either the block or the head if one or the other warps enough to unseal an MLS gasket, but nothing obvious on this engine.

[@davidclark7584]

I have a 2015 Mazda 6 with the 2.5. For a non turbo 4cyl it has balls. The 13 to 1 compression really shows. Close to 70k and no issues.

[@know916bound]

I love my 2015 Mazda6. It has 171k currently. Regular maintenance and tranny oil changes. But everything is original minus spark plugs and top engine mount recently. It still drives like new and gets 40 mpg on the highway when i do the speed limit.

[@theseph28]

The non turbo Mazdas are great.

[@aliefdrumline]

Same, I love it. 2016 with the 6 speed manual and a few goodies. I have no complaints nor the car complain about anything.

[@jawsgreatwhite9966]

I’ve heard people complain about the 2.5 naturally aspirated engines on their power but I find this to not be a problem for me. I think it has plenty of pep and 187 horse power for a four cylinder is pretty impressive in my book. Mine is a 2023 CX5 and it’s been a blast to drive.

[@Kevin-bi9nf]

do they require premium fuel with that compression ratio?

[@johngassmann9581]

The first car I bought for myself was an '04 Mazda 6. I had it for about ten years and never had a problem with it. It was a great car.

[@TrollinCrazyRussian]

Years mean jack shit mileage/hours is everything. What mileage purchased at? What mileage sold at?

[@old_guard2431]

The “hours” part is important, but may be hard to track. Industrial engines often have hour meters on them. With all the electronicals monitoring the system it would not be hard to track that, but I honestly don’t know if they do that. The fact that my Honda Element runs so well after 17 years and 230k miles is probably related to somewhere between 30% to 40% being highway miles, ticking along at about 1,900 - 2,100 rpm in high gear full warmed up.

[@Truth-op3be]

I just purchased the 2024 Mazda CX-30's carbon edition Skyactiv®-G 2.5 Turbo .” And have heard great reviews “

[@Flyr264]

The Mazda Skyactiv engine line will be ones to remember. Long live Mazda!

[@The_Noticer.]

Yeah, remembered for its ridiculous market segmentation. They just half-close the throttle on the lower trims. Who still does that? The 120HP 2.0 is the same block as the 165HP GT-M, just the throttle gets fully opened.

[@AskTheEight]

@@The_Noticer. bro what are you on lol

[@powdereddoughnutdisaster5531]

@@AskTheEightthey’re talking about the Euro cars. North America doesn’t get the low powered 2.0.

[@AskTheEight]

​@@powdereddoughnutdisaster5531 Correct

[@jmc8583]

@@The_Noticer. A bit late on this, but... it's not what you describe. Low power variant just has a different injection mapping, limiting power past a certain arbitrary rev limit. While I find this stupid, in fact, for a common driver it has ZERO impact as (s)he will never go beyond 4k rpm. What's annoying, though, is the decision to give these engines a perfectly insane last gear transmission ratio, to the point the 120 3 feels unresponsive and often requires you to downshift in normal driving conditions. I don't know for "old" 75/90 2's (current 90 ones inherited the 115 "short" 6MT, still not that "short" by the way, but actually perfect for city/road use), but I suspect it's even worse; at least, their engines won't suffer as much from the excessive flywheel inertia as you'll not be inclined to push the revs (that's THE thing I dislike the most about my 2).

[@thetechlibrarian]

These engines drive so nice for only 186/194 horse power. They make almost all there peak torque from 2k rpm to 4k rpm. During normal driving it feels really nice. You can take big hills even without having to downshift.

[@Jihadbearzwithgunz]

Much better then the early ford/mazda 2.3s those were gutless dogs drove a 95 ranger with one from Colorado to California and man the hills beat it up would pin it at 85mph at the bottom of a hill and by the top we might be going 50mph getting passed by big Riggs

[@Dcc357]

A 2.5 liter is above average in displacement for a 4 cylinder, so expect better torque for sure.

[@ForsakenLiye]

@@Jihadbearzwithgunz before my 2016 Mazda 6 GT I had a Mazda 3 with the 2.0 and that thing would fly around easily

[@rudolphna54]

@@Jihadbearzwithgunz My old roommate had a 2008 Escape with the 2.3L and the 4 speed auto. Gutless dog is honestly generous to that powertrain.

[@Omgninjas2]

We even used our 2016 CX-5 to tow a pop up camper that was in the 1600 lb range. Car did pretty damn well for a little 4 banger. Everything we've ever thrown at the vehicle it just keeps on going. It is just a happy little SUV.

[@alwaysamongdragons7354]

I've owned three different vehicles with the Skyactiv-G engine and currently drive a 2022 Miata. At least one was a Mazda 3 with the 2.5 G series engine like you have here. I am very intrigued by this! I love seeing engines I've actually used torn down. After watching the rest of the video, this is how my 2001 Protege from Mazda failed. Overheated (my radiator reservoir burst on the highway and my temperature gauge was maxed before I knew what happened), and the head gasket warped, effectively broke seal, and started pouring coolant into the cylinders.

[@seanthompson8071]

That was my guess for this engine ... something went through the radiator on the highway.

[@alwaysamongdragons7354]

@@seanthompson8071 Probably. My particular case was just an old radiator with brittle old plastic, but still produced very similar results to what an impact to the radiator might if it is bad enough.

[@cbsharpe0824]

My 2023 CX-5 AWD has been great. This has been one of the best 4 cylinder engine cars I've owned. Look forward to putting many, many miles on it.

[@emissionfreeworld]

Greetings, I'm new to Mazda world and will be acquiring a 2021 cx5 signature with 18k miles, 1 previous owner clean throughout certified for approx $23k. My question to you, have experienced any problems or issues suspension, cabin noise or body sway?

[@cbsharpe0824]

@@emissionfreeworld Mind you...I have a 2023 so I cannot comment on the 2021 version but I have not experienced any of those issues.

[@danivasquez2441]

Do you have the 2.5 or smaller engine?

[@houtyfish273]

Hey, thanks for that great video! It confirms for us Mazda fans why we love our cars so much! By the way, looking at that engine, I suspect foul play. We have 2 Skyactiv 3's with well over 100 000 on the clock, and no carbon, no rust, nothing! They are super reliable.

[@Raventail2]

A very simple and elegant engine design. Very refreshing to see after that BMW HOT-V N63 teardown. BMW could learn a few things from Mazda about engine design.

[@burntnougat5341]

Well they're two different beasts. V8 and inline 4. Bmw does inline engines pretty wells especially the i6

[@Atixtasy]

yet they never will because "german engineering" lol

[@86FxBdyCpe]

They should start by learning how to design non-leaking oil pan, valve cover, and filter housing gaskets.

[@syloui]

We'll see how Mazda's new straight 6 stacks up

[@QuincyStick]

​@@sylouigiven their success with other engines, I'd be genuinely amazed if they managed to fuck an I6 up lol

[@markcollins457]

For some unknown reason everytime I see oiling lines I think way back to the old Toyota land Cruiser they supposedly based it on the Chevrolet inline 6 but perfected the weak points and made them better than Chevrolet by adding overhead oilers and better valve seals. That's why I enjoy the teardown it shows the good and gooderer!

[@billbaber6653]

Thanks for the entertainment

[@detaart]

These are very reliable. I've had 2 mx5s with skyactiv engines. One ND2 2.0 and one ND2 1.5 which is a rental car until my new ND2 2.0 comes along. I put about 80K km on the first one, about 25 on the current 1.5 loaner as well. Zero issues. The 1.5 seems more eager to pull timing on hot days though, and it is noticeable. Fuel economy is phenomenal for an NA engine as well. I beat on them quite a bit (because miata), and absolutely zero issues. The only thing is they can be a bit rattly at idle due to the HPFP.

[@louiscabral7306]

I currently drive a 2016 Mazda CX5 sport, with 33,000 MLS, all services are current, regular oil changes, I've had it since 2019, no complaints

[@ckhound1]

love my 2016 Mazda 6 GT with the non turbo SkyActiv, such a reliable engine. Glad I went with Mazda. Currently at 110k miles and rolling along.

[@JoshMandelberger]

I’ve been waiting to see a Skyactiv 2.5! Thanks for giving me a view into the engine that powers my CX5.

[@supertruckertom]

How do you like the CX5? My wife is wanting one to replace her 2018 Ford Fusion SE 1.8 Ecoboost that is at 105k miles.

[@JoshMandelberger]

@@supertruckertom I love mine. I've got the NA version, and really enjoy driving it, I've heard lots of good things about the Turbo versions too. Turbo version has a lot more power of course. Overall a great vehicle in my opinion.

[@StreuB1]

Very impressed by this engine. Lots of really good engineering here and nothing that is done in some off-the-wall crazy manner. Just good solid design work. Its also a simple engine as well, likely lending itself to the reliability.

[@shadowof1155]

I have a 2.0 sky active on my Mazda and I love it, iv put it through hell and back and she still purrs every time I start her up ❤️ of course maint. Is always up to date and prev. Maint. Is done regularly.

[@braptechfun6036]

I work at a Mazda dealer in europe, Cyl4 spark plug IS ALWAYS WET AND LESS TIGHTENED (with a wet thread) than the rest of the plugs, on all the G’s I’ve replaced spark plugs on (a lot). Spark plug replacement at 120k km (iridium ILKR7L11). No issues with engine smothness before or after. Did some compression tests on newer G’s and it’s the same situation. My guess is the automated assembly machine that drives the plugs in looses torque at the 4th plug after doing the former 3 plugs but I don’t know for sure obviously.

[@notsureigaf]

30 seconds in and feeling pretty good about my Mazda 2.5 😆 I did a lot of research before buying this car fresh off its first lease, since I tend to hang onto my cars until they're basically undrivable. 4 years and 50k miles later I'm yet to be disappointed. Hopefully it'll stay that way for awhile.

[@c0c0asauce]

I have a 1995 Miata. I got it shortly before it turned 222,222 miles. 1.8 Rebuilt for boost at 232k. It has just under 239k now. I'll get around to boosting it this winter hopefully. I imagine Mazda is the kind of company that wants a failed engine back for analysis most of the time.

[@jamesmedina2062]

not always

[@matthewbowen5841]

Can we take a moment to marvel at Mazda engine tech over the years? The Wankel, tiny displacement K series V6s, the Miller Cycle, the dual and triple rotor turbos, the proposed Amati W12, the compression ignition Skyactivs... I was surprised to see this engine pop up as a teardown, as they (and the modern Mazdas they power) seem to be some of the most low maintenance, robust cars available in the past 10 years. Just make sure you replace rear shocks regularly... Knowing how rental cars are used, I'm going to make an educated guess that the cooling system was punctured due to an impact of some sort and the car was driven until it overheated. The engine was a casualty, not a cause.

[@confuzionn4843]

I see so many Mazda3s and 6s still just roaming around today. My 180k miles Mazda3 still chugs fine, and in offered in a manual too!

[@cumbob]

They have had some cooling system leak issues recently with these tho. They do have a lot of great engines though. Lot of firsts in the industry too like active intake runners and sequential turbos and hcci

[@harrywalker968]

wankel, rotory,,2nd ww..german..

[@HierarchyOfWeeds]

@@confuzionn4843 remember to do that timing chain before 200k and it’ll go for 250+

[@confuzionn4843]

@@HierarchyOfWeeds thanks for the heads up.

[@jaredbawden6707]

Thanks for this teardown Eric. I like many others on here have been curious to see the innards of a Skyactiv engine. Nice to see Mazda banished all the Ford defects of the MZR series. Shows Mazda still has the knowhow when there's no outside interference. I'd love to see you get your hands on a K-series engine. I still have a 323 hatch with the factory 2.0 KF V6. Such a sweet engine that just loves to be revved like crazy.

[@spamcan9208]

I'm so jealous. That little V6 sounds amazing.

[@jaredbawden6707]

@spamcan9208 they really do. It's not real fast by modern standards, but I love the sound every time I put my foot into it. Was originally going to sell it, but after driving it again full time for the last 9 months, I'm not sure I can bring myself to.

[@-All5ofus-]

Im on 50k on my cx30. Notta one problem. In fact, it's gotta be the best 2.5 I've ever owned, and I typically by Toyotas.

[@Chris_de_S]

50 k? Still brand new.

[@jayinmi3706]

My dad had a GLC in '78, which he replaced with a GLC Sport in '81. I got my 2015 6 in 2017 with 34k on it CPO. It has been HANDS DOWN the best car I've ever owned (I've been driving for 33 years). In the 6 years I've owned it, I have replaced brakes, tires, fluids and 1 alternator belt. The car just topped 243k miles this month. It's the first car I've owned that I didn't really want to replace after about 3-5 years. This was interesting to see the internals of and looks like it was well thought out and easy to work on. Neat video.

[@budlanctot3060]

Really impressed by how clean the engine was internally, except for the chocolate shake in the pan. Nice to see perfect bearings & crank.

[@rylandsilva]

I have over 310k miles on my 2015 Mazda6 non-turbo. Still running strong!!

[@CrimsonLegacy]

Wow! Congratulations! You've got me curious, though, what are you doing with the car to rack up that many miles?

[@rylandsilva]

@@CrimsonLegacy Just used it as a commuter for many years. It required countless oil changes needless to say and I exclusively used Mobil 1 synthetic.

[@devdoesitbest6974]

My sister has a 2013 mazda 3 with over 200k miles. When she got it with 180k she didnt know you had to change the oil and went over 20k without an oil change. Still running strong somehow

[@DrPowerElectronics]

Older engines will be rubbed nice and smooth already 😊😊😊

[@djrenault]

i'm at 335k km on my 2012 2.0 skyactiv and still going strong. very neat teardown

[@bigorsmallfishing9019]

Wow, cool to hear about you being a Mazda fan. I've owned 4 1988-89 MX-6 GT Turbo manuals back in the days. Upgraded them to about 250whp and smoked a bunch of cars back in the late 90's and early 2000's. Missed them, still looking to find a nice clean original example.

[@chuckz8053]

Thanks again, always like your Saturday night shows. I've had three Miatas, currently own a 21 RF GT. The engineering and build quality are impressive and driving the car is a real joy.

[@virtuosoification]

"i dont know why i do these things " because its fun eric ! and youd still do it even if no-one was there with you , so would i ... thank you for your content

[@csjrogerson2377]

Some of the 2.2li skyactiv D engines have had head-gasket problems. Might be a similar issue. As for my 1.5 turbo diesel Mazda 2, runs like a dream after 70K. 50-60 mpg (US) and 600-700 miles per tank for $45. That's a gnats hair off electric costs per mile and when prices return to normal, it will be the same and its a $20,000 car, not a $50,000 4-wheeled-hair-dryer. Diesel rules.

[@TEMPLE7D]

HolyCrap! finally got one of these?! Never thought you would lol. These Engines are AMAZING! Been asking in the comments for years now lol. 2.5T is really great too, despite the recent gasket issues. 140,000 miles on my 2018 CX-9.

[@howardhandville2107]

Great video! My 1st Mazda was a used 5-speed manual '86 626 Turbo Hatchback. It towed a 19 ft fishing boat between the Keys, Fort Lauderdale and Naples several times. 2nd Mazda was a used 2011 CX-9, and have thus far put over 185k miles on it w/original engine & tranny (normal maint). My great experiences with the brand prompted me to buy another used Mazda last week (2021.5 CX-5 Signature). I'm sold!

[@Upsh1ft]

I have the 2.0L Skyactiv-G engine in my 2014 and over 200,000km on it and the engine still runs like a peach in spite of the fact I basically redline the thing daily. I am very stringent on the oil changes though which likely helps.

[@mutantyep1]

Me too having same engine in my Mazda 5 MPV (2017). Bought it recently at 102k km, now at 122k km. How often you change your oil and which viscosity and brand you like most?

[@Upsh1ft]

@@mutantyep1castrol Edge or the Mazda branded 0w20 oils are my go-tos. I stick to the Mazda oem filter. So far so good.

[@MypurpleMoonLake]

I own a Mazda6 2020 with 425K miles on it. Been everywhere in USA and Canada without any issues. Best 20k I ever spent!

[@Buck58]

Yeah, I've got the 21 Mazda6, been good so far..

[@prydin]

Really neat little engine. You’ve struck the perfect balance between exploring engine design and relishing in catastrophic damage. The channel just keeps getting better!

[@Darbman62]

I like that they went back to a steel pan. My wife's CX-5 had an aluminum pan and the steel drain screw pulled the threads out of it after two oil changes using a torque wrench to tighten the plug, so I helicoiled it. No trouble after that, but it was just annoying to have to do that.

[@ScottJ175]

Had to subscribe because your a fellow Mazda guy. I've always admired them but never owned one until buying my wife a brand new Mazda 6 with this same engine in 2018. Since getting it my collection has expanded to include a '96 Miata, '09 RX-8 bought with just over 7k miles and now just over 15k, '08 Miata and '82 RX-7 derelict I hope to save (have 2 parts cars to go with it). I found your video searching on Skyactiv G because the 2018 after over 107k trouble free miles gave us our first scare with a failing coil pack a couple weeks ago. So as it moves on into aging hooptie territory it's time to learn more about it. This video helped a lot.

[@RtB68]

My wife drives a 2018 6 with a 2.5 turbo and it’s great. I’ve flogged it like a beater for 5 years and it’s oil is still clear and no issues with 100k on the odo. Maybe we got a good one, but it’s a fantastically good family hauler.

[@gregroles69]

Very interesting, indeed freaky pistons, odd to have sharp edges on top. Anyway, I trust Mazda to know what they are doing. Nearly bought one of these engines in a new CX-5, and researched this engine in depth, so really enjoyed the teardown. As a diesel guy a lot of this engine makes sense now in how it is designed to work, and it's always interesting to see "different" engine designs, you can never know too much.

[@Z4Zander]

Google SkyActiv-x pistons.These are for the newer spark controlled compression engine.Runs 16:1 on 87 RON.🏴‍☠

[@gregroles69]

@@Z4Zander sharp edges anywhere in a combustion chamber become hot spots and can lead to preignition, especially at high compression! Perhaps that's the plan, who knows..

[@yodasbff3395]

Good teardown, I always wanted to see how these engines looked on the inside. They look like a very well designed engine. Thanks. 👍

[@jackpatteeuw9244]

Modern version of a Ford PROCO ?

[@chivalryremains9426]

I had a 2013 Mazda 3iTouring Hatch with a Skyactiv engine. It was the last year of the Ford-influenced body and the first year of the Skyactiv engine. It drove like a dream and I was able to get 42mpg out of it traveling the flat rural highways in Eastern NC. What let it down was some weird catastrophic electrical problem. It happened twice. Once at a traffic light and once accelerating up a hill at about 30mph. The entire engine would quit, dash would go dead and everything but the radio would stop working. Thankfully I was able to brake. It required me to shift back to Park, switch off the ignition (push button), then re-start it. And after that, it ran fine like nothing had happened. It was under warranty so I took it to the dealer and they were unable to find the cause. I traded it in for a Honda because I was afraid it was going to die on me traveling 70mph on the highway. I loved my Mazda and it broke my heart to get rid of it. I want one again.

[@know916bound]

Definitely not a common problem for the mazda3 but 2013 saw the first year for the new skyactiv platform for the US, and did see a few weird problems like the one mentioned. But they've come a long way since and newer 3s are super solid.

[@chr103yod]

I have a 2013 mazda 3 with a 2.0 Skyactive. I have 250k miles on the car. No problems other than an alternator. Original clutch. Awesome vehicle.

[@solderbuff]

Thanks for sharing your family history of owning Mazdas. I've owned a 2010 Mazda 3 for less than a year now and I'm already a diehard fan of this brand. I love how they combine innovation with simplicity and reliability, while making cars which are fun to drive. Also, they are constantly among the safest cars in N/A according to IIHS, outperforming other Japanese brands in terms of safety.

[@lttsr]

The SkyActiv motors are really really good. Very impressed with how reliable they are. I feel like not enough people are talking about them

[@douglasthompson201]

It amazes me that Mazda sales aren't higher. Every person I know who gets one ends up loving it, whatever the model. Mazda dealer techs where I work also work on other cars from the used car sales side too supplement hours, as the Mazdas alone don't come in for service repairs beyond basic maintenance to keep the techs fed.

[@xxkylexxredhead]

​@@conordevery2306 that's an interesting take. Haven't seen many people complain about the build quality. What makes you say that?

[@MisoElEven]

@@conordevery2306 If you want to see bad build quality try a Dacia or a lower end Renault :D 50k km in and the drivers seat will just quite literally fall apart (no tears in the seat just the insides will crumble), the engine will start to burn oil, first rust spots will appear, doors will start to feel saggy, the airbags may fail to deploy in a 60kmh crash (60kmh after braking from 150...personal experience with a Dokker :D) causing very "pleasant" pain in your neck for the next 2 weeks.... thankfully not my money and not my cars but still, theyre quite crap.

[@MisoElEven]

@@conordevery2306 It can do 185 with the 1.3 turbo engine :D it just goes left and right randomly but it is possible to keep it on the road

[@neonnoir9692]

Good, keeps them cheap for us.

[@anthonygregg862]

That was an amazing teardown. I am on my 5 mazda 3 and they are brilliant cars. I have a 2L Skyactiv X in mine and its such a good driving car especially on the motorway. Lots of torque for a 2L.All your teardowns are simply fab. Cheers Mate.

[@yuriteixeira5816]

How is the X? I was a salesperson for mazda in the states, but we never got much information on them

[@anthonygregg862]

@@yuriteixeira5816 The X is a great engine. It has a different compression set up to the G. It uses both petrol and diesel qualities. Its a 2L with 186 Hp. We only get the lower power engines here in the UK. Its a great car for the motorway its a mile muncher. The torque is also strong for a 2L and very tractable. Pulls well from just over 1.5K. Its also very economical. I get approx 40 around town and 50 on the motorway using the uk's imperial gallon. say -10 or so for the us measurements.

[@abdulsalamnangi3409]

Hi Eric… I was browsing for the review of CX 60 recently launched in ME. I’m glad to see such an amazing video. My first car was a 1990 YM Mazda 929 5 speed MT. I never had any problems with that. I was using it for quite long, about 20 years. After that I was using different types. Now I’m planning to go for a CX 60 2.5 Skyactive G RWD AWD. I’m not happy with the options of available trims. Waiting for the new trims to come. Your video helped me to learn more about the Skyactive G technology. Awaiting your next videos… Thanks.

[@d-day67]

I was surprised being a Mazda fan myself, that you didn't show the M3 hatchback. I had a 2004 manual, quite honestly the most fun to drive of all my mazda's. the MX3 v6 was a fun car too.

[@tripresidue]

I got suggested this probably because I've been watching a lot of CX-30 videos. Now I'm subbed and bingeing.

[@josephfrunzi4606]

I used to work at a franchise shop that serviced the rental cars for a company that had a name that rhymed with Enterprise. Not only would people drive the cars like they stole it. But the company wouldn't pay for the required oil grade, also they wouldn't pay for more than 5qt's of oil. So if the car or truck called for 6.5qt's of synthetic 5w30 we would be required to put 5qt's of 5w20 conventional.

[@richardflagg3084]

Rhymes with 🤣

[@kendallsmith1458]

Own a 20 CX30 and I will NEVER tear down a 2.5. But it is great to see how well it's built.

[@jawBtan1]

This is awesome (for lack of a better term)! I own a 2019 cx5 with 30k miles and absolutely love the car but it’s crazy to see the engine like this. side note, also a Mazda fan, as a teenager in high school I had the coupe mx6, 1990 was a great fun car to drive!

[@MidlifeCrisisManagement]

on our third CX-9, the second one with this engine. have also previously owned an MPV and a 2nd-gen RX-7. this engine teardown was well-executed. for as much abuse as this engine took on, it looked surprisingly in-tact. the current version puts out 250hp and 320lbft torque with full-time AWD.

[@alexkinnane5831]

I've had our SKYACTIV-D 2.2LTR (SH) DIESEL ENGINE from our CX-5 blow a head gasket revently. Been trying to find a solution as apparently it is a very big job and is likely an engine out deal. They have had a recall on this type of engine but it unfortunately doesn't extend to the headgasket side of things. They were only covering some vaccum issues and some accociated issues with direct injection. The joys. Keep doing your thang! Love all the videos!

[@Junk65]

Mazdas are great cars. I’ve owned many. Usually the only issue is a blown head gasket due to plastic radiator. My current mazda overheated at 267k miles due to thermostat-cracked radiator. I would buy a new Mazda without hesitation.

[@bigcrowfly]

Mazda is putting Cylinder Deactivation (displacement on demand/other names) on all non-turbo 2.5 4cyls in recent years, but not for long enough to show high mileage problem trends. Once large numbers of these cars (that have operators whose driving style activates the CD) will see if Mazda does CD/DOD better than others.

[@Givelasagna]

I'm a tech for mazda for 12 years. So far the CD system on these skyactiv engines have been bulletproof with no issues whatsoever, even with older models.

[@davidb6576]

@@Givelasagna Any opinions on the possible failure modes of this engine?

[@frankd.3985]

According to the inside display, all 4 cylinder can de=activate when no engine powerf is needed. At low power, only the inner cylinders deactivate. The cylinders don't de-activate very often. You have to completely close the throttle to de-activate all 4, and just barely touch the accelerator to have it switch to 2 cylinders. With only 2.5 liters, you don't a lot of excess power normally.

[@Givelasagna]

​@@davidb6576 what do you mean by failure mode?

[@dans_Learning_Curve]

​@@frankd.3985 "All 4 deactivate." Does the engine restart on its own?

[@CharlesVanNoland]

Just gonna say, I've got a thing for these little motors. They're just more appealing to me for some reason. They have to get maximum power from a minimal package.

[@roberthdavisii]

Ughh...the memories, watching your scroll of the former cars and trucks you've owned...truly an eclectic and fun selection

[@Sinflux420]

My 2016 Mx-5 is still purring along at 70k miles, absolutely love it. It'll always be my little Red Barchetta, hoping it runs well past 300k. Awesome breakdown, these are great engines!

[@maxxbenzz7842]

Love the Rush reference 😊

[@jdsk8914]

Aww ❤

[@terencerucker3244]

Even though there wasn't any carnage, it was interesting to see how the Skyactive engine was engineered and built. I have to say I'm impressed. I'm especially impressed with how they managed to run the gear train so simply. Like Elon Musk, I subscribe to the "best part is no part" philosophy. No wonder a previous poster said that the engines are easy to work on. Compare that to one of the BMWs or Audis you have had to tear apart! As usual, a lot of fun. Keep 'em coming!

[@jphammah9509]

The Skyactiv engines are so cool. Inside the intake cam gear is supposed to spin like that because there is a EVVT (Electronic Variable Valve Timing) module that sits in there and will obviously control timing but I absolutely love these engines. So easy to tear down. Great video!

[@DavidMcConnachie]

Great video. If I'm not mistaken there should be a tapered plastic sleeve in the cooling jacket around the cylinders to modulate cooling up the cylinder wall and focus it around the combustion chamber. If this is missing, as it appears to be in the video, then the head temperatures could exceed the gasket design.

[@devinosullivan7849]

I own a '16 mazda6, my wife has a '20 CX5, our oldest daughter drives a '10 mazda6. Not a single repair needed. Just maintain and they get you there and back! Cool video, and always wanted to see inside the engine.

[@Chris_de_S]

Those cars are still new booster. Were you expecting repairs in the first 1 years?

[@crodrc51able]

My parents owned a Mazda MPV, 2005 for 19 yrs. Sold it with 225000 miles. Only had a trans rebuild, they never changed the fluid so that was on them. They recently bought a 2021 CX5 with the NA motor. Phenomenal cuv. Great quality, butter smooth, strong enough motor, plenty of room, nice interior, elegant look. And they have the base model. I’m sure it will last them a long time too.

[@michaelmartinez1345]

Interesting episode Eric!!! What was of particular interest here, was the composite head gasket failure, which was not the only thing that failed.... The head and block are both made of aluminum.... Aluminum typically looses it's tempering at about 475°F. The overheat could have caused the Aluminum in the part of the engine that was the hottest place of that engine to go above the critical temperature of 475°F. And it's possible that the annealed aluminum female threads holding down the head, started to fail and allow a partial release of the down force of the head, being provided by the head bolt(s)... And with a ridiculously high compression ratio of 14:1(for a spark ignition engine), that block should have been made of cast iron like the vast majority of truck diesels are with that high of a compression ratio... If the annealing of the aluminum from an overheat did occur, then this engine is probably a victim of design flaws....Your most interested customer of this engine, just might be Mazda, to see what could have caused this engine of theirs, to fail with only 30k. miles....My guess is either they lower the compression ratio or they control the overheating which was probably caused by detonation, by retarding the fuel burn to begin AFTER TDC by using another program on the direct injection system, THUS REDUCING POWER AND EFFICIENCY...The people at Mazda seem to be pushing the limits with this engine, using diesel engine compression ratios with pump gasoline... The first sign of this engine developing excessive heat, was the use of the two lube rails above the camshafts, to be able to provide lubrication in critical places during extreme heating conditions... And to help carry away the extreme heat build-up on the head... That engine oil pump is HUGE for that little 4-banger... It's purpose goes well beyond lubricating this engine... It circulates BUCKETS of oil to help this thing keep it's cool...

[@ShadowwwLFS]

BMW M57S, N57, B57 3-liter diesels (and equal 48 2-liters and 38 1.5-liters) are all aluminium, and are known to be extremely reliable.

[@elmura73]

I think if it was a design flaw, you'd be hearing about it a lot. Certainly it is a highly stressed engine, which means that if something doesn't fall within design expectations, failure is imminent. Perhaps, being out of a rental, and being driven hard is what caused it - because it exceeds the target operating envirnomnent. Or that it was run on low octane fuel AND driven hard. A recipe for disaster on a highly stressed engine.

[@michaelmartinez1345]

@@elmura73 You could be spot-on about rental vehicles, often ridden hard & put away wet... But aluminum has now become so common to use as major castings on many types of engines, that it is an accepted standard among the buyers... What people might be overlooking about aluminum castings of major components, is that a single overheat could completely make that casting unusable... Where cast iron can survive numerous overheats, and still hold together just fine.... I'll stick with the cast iron castings, Thank You... And the octane rating of fuel is very important to prevent self ignition and thus detonation- on spark ignition engines with the fuel being introduced into the airflow path before entering into the combustion chamber(s)... But on direct injection engines, where the fuel is pressurized to high pressures, the octane rating of fuel might not be important because of the absence of oxygen in the fuel delivery flow path... But what if oxygen is inadvertantly introduced into the high pressure fuel flow path, what are the chances of UNWANTED self ignition of gasoline, that could take place??? This could be interesting to see what could happen to gasoline in those conditions....

[@michaelmartinez1345]

@@ShadowwwLFS That is very possible, provided no overheating exists... Also, engines with undersquare (piston bore diameter is smaller than the length of the stroke) designs, tend to have less tendency to detonate, especially when they are directly injected, as the fuel burn can be started much later than a spark ignition engine typically does... The problem when using gasoline in extreme compression ratios, is it's tendency to have much less resistance to self ignition , as diesel fuel does... Another thing about gasoline, is gasoline also has very poor lubrication properties compared to diesel fuel. So high pressure pumps pressurizing gasoline tend to fail more frequently than high pressure pumps pressurizing diesel fuel... But if a diesel engine overheats, especially if it is made of aluminum, they usually require extensive $ to repair.... All of those car types , that you mentioned, are for those who have a LOT of $... The money will also be required for repairing those vehicles when problems like the ones shown here occur... A LOT MORE $ will usually be required for their upkeep, mainly because of their exotic designs....Most people just want something that they can depend on, without $pending huge amounts of $ to try to keep it running... Mazda is known for making cars for those who have modest amounts of $ to upkeep them... This is WHY, I suggested to Eric to show this engine to it's creator, so they can examine what went wrong.... And know what to avoid in the future...

[@matsudakodo]

​@@michaelmartinez1345 yes, API SP and GF-6 oil standards were created to reduce low-speed preignition on these engines. One of the changes is to reduce calcium which was found to increase the risk.

[@ADrones13]

finally after many videos of requesting you finally tore one apart. Great video and can't wait to see other engines you teardown

[@thetechlibrarian]

Same I was genuinely excited to see the notification. This is the only video on the entire internet as far as I know of this engine being disassembled.

[@jdub976]

@@thetechlibrarian could not find another one myself either. Rare to see these torn town. Was great to finally see one.

[@stephenmurray2851]

I adore mazda. On my second one now. Love them. Stunning reliability.

[@Chris_de_S]

What car did you drive previously?

[@stephenmurray2851]

@@Chris_de_S fiesta.

[@Fadamor]

I have a 2023 Skyactiv-G 2.5(T?) CX-30 that I bought used in February. It only had 17000 miles on it and based on some of the documents included in the glove box, the previous owner was Avis Rental Car. I put the "T" in parenthesis because I didn't think I had the turbo version, but when I went to get the oil changed they had to put 5.1 quarts of oil in to get the oil level up to the "Full" line on the dipstick. The 2.5T is the only version in the owner's manual that takes 5.1 quarts.

[@Guido_Sarducci007]

"Carnage and debris". Two of my fav words. Really enjoy these tear downs! Thx!

[@crimsonstang]

My sister's 2016 CX5 failed at just under 61k. Head cracked and leaked coolant and oil into the spark plug wells. Out dealer replaced it for free out of warranty because the issue began inside the warranty period.

[@Chris_de_S]

SAD

[@skullyairsoft80]

Good to hear that these motors don't seem to fail often. Slightly different to the 2.0 L in my '22 Miata but similar enough. Very interesting to see the differences between this and older Mazda engines

[@davechapman7735]

a very well done and explained tear down. thanks for showing us. here in NZ we have loads of these on our roads and its great to see how they work. cheers NZ

[@gooniac33]

There have been head issues with these engines. Not all of them have issues but mine did! The turbos have a casting problem that acts like a bad head gasket until you get the turbo off to see under it. not sure if that was the issue here but I saw the coolant on that one side of the head that looked like what happened with mine. With my car Mazda Corporate paid for a new head and headgasket in the amount of about $5400 because it was their fault for the car breaking even with the 94k miles on the odometer. I have done all the maintenance and nothing was missed... I never even let it overheat! As soon as I noticed a fluctuation in temps I stopped and checked coolant. Noticed a misfire and then eventually coolant out of the exhaust. Cyl #3 had coolant leaking into the cylinder and was fouling the spark plug. Again its rare with the NA engine but there have been a few issues with them as well. Nice to see that almost all else was in great shape on this tear down though! They did a good job with these engines! My wife has a 2016 NA 2.5L in her CX5 and its been an excellent car!

[@OneLeggedStormChaser]

It’s awesome to see how you can be objective unlike most others!