2016 BMW F80 M3 Twin Turbo S55 Bad Engine Teardown. Bogus Rebuild?

[@allenl9031]

Theory, the original car this was in was totaled early in it's life, but engine not damaged, removed, bought by a rebuilder, that just removed bed pan to check a couple of bearing, hence the looser sets of main caps, looked good, buttoned back up, broke pan bolt, ignored it. So, put on heat tabs, rattle can paint spray. Sell. Bought as a "rebuilt" engine, then abused by the next owner.

[@cirian75]

sounds about right.

[@t-yoonit]

Accurate.

[@williameverwine9404]

That's probably what happened

[@BruceLee-xn3nn]

Sounds like you've done this before.

[@infidel900rr]

...Next owner, had a manual trans M3, with BMW's inaccurate "rubbery" shift feel and accidently went from 6th to 3rd flying down the highway at 11pm, half drunk and listening to hip-hop while boasting to his online date about how fast his car is. Mystery solved.

[@crpgap9595]

If I had to guess, I'd say the rebuilders decked the warped head, added a +.3 head gasket, and called it a day.

[@alflyover4413]

That is a better fit for the pieces that came out than my guess. Somebody trying to smooth out a warped head is more likely than somebody trying to raise the compression ratio a couple of tenths for more power from a turbocharged electronic engine.

[@crpgap9595]

They probably checked the bottom end too but left it alone. And that top timing cassette bolt was over torqued.@@alflyover4413

[@samh6761]

Great demonstration of the valve-tronic mechanism. I don't know if I'll ever work on one of these, but I learned a lot.

[@michaelwalton3631]

I've accidentally rebuilt the valvetronic from one of the very poor siblings of this engine, the n46 4cyl. Accidentally because I actually wanted to remove and refit it as a unit while doing valve stem seals, but my cable tying was sub standard... anyway, not that difficult, no special tools needed despite rumours to the contrary. What i wanted to say is, its actually a very elegant and pretty simple bit of engineering imo. Not much different from the time tested ohc besides the electric motor. Nice to see a video of the mechanism in action.

[@godmodeforever]

Watching you tear down engines week after week makes me realize just how insane automotive engineers have gotten.

[@williamshappley2106]

Especially German ones…

[@Pozi_Drive]

@@williamshappley2106 Don't rule out the nippons.

[@GoldenCroc]

Well yeah, the poor buggers had to...

[@kennethross786]

There's a lot of shady shops out there. I remember talking to a transmission repair shop manager (my tranny had just deleted 2 of its 5 gears on the interstate at 70 mph, so I drove it 300 miles to my destination on the 3 gears I had left). He told me he had taken a chance on buying a "rebuilt" engine from an auto parts store, only to discover the "rebuilt" engine had a blown head gasket - the exact same issue that the engine he was swapping out had! On the plus side, glad you're going to make some good money off the remnants of this engine.

[@macthemec]

Valvetronic isn’t an answer to a question nobody asks, it eliminates pumping losses, a question that has been worked on from the 325e to turning the throttle pedal into a torque request meter. When you think about it, a rocker shaft is old as the hills, make it cammed so it can vary the rocker lift and have the “gas pedal” for lack of a better term act on that instead of a butterfly valve controlling air flow. I also like the failsafe they built in where in a complete failure the engine will work like one without valvetronic and operate on the redundant valve body, smart thinking

[@GoldenCroc]

Exactly, it was a question, nay demand, from many european customers.

[@willemb8689]

Exactly! And prefect throttle response!

[@jamesgeorge4874]

Reduces, not eliminates pumping losses.

[@GoldenCroc]

@@jamesgeorge4874 He probably meant in the context of the throttle plate.

[@DefaultLoginDetaiIs]

Those cam trays are also valuable. They are interchangeable with the N54 and N55 engines and there was a design flaw in the N54 which meant they commonly wear out early causing low VANOS pressure. Maybe £400 for the pair.

[@jacquesc3166]

Didn't think I'd learn something about the N54 in this comments section, but thank you...

[@tomschlachet4310]

During a post-mortem, it's good practice to confirm mechanical timing before removing the timing components. Doing so will help you better determine the cause of any witness marks you may find. Hand turning compression may have felt and sounded OK, but I bet each one of those exhaust valves were bent just a little.

[@julesviolin]

Eric often does just that . 👍

[@KartmanPCR]

No intelligent person is going to use that head without checking EVERY exhaust valve.

[@Benton0812]

thank you for my mental health reset as always, watching you do a tear down is so calming

[@dustcommander100]

Best engine I've seen you tear down, and I really believe you deserve a lot like it. In fact, I was thinking you might rebuild it and put it in one of your project cars. I just can't relate to BMW's, but I'm amazed by your knowledge of them. If anybody can successfully navigate the pitfalls on those cars, it is you. I'd lose my shirt!

[@jonsmith1914]

Congrats on finding a good score with this engine. I've been watching your channel for almost a year now and it keeps getting better and better.

[@nickolaswilcox425]

got to see an engine with inspection ports and a piston delete in person today, helped to remove it from a solara, lack of oil, but hey, it still turns over and two of the pistons still seem okay, one had the crank bearing section of the rod shatter and get pulverized and its neighbor got a bent rod as a consequence, im hoping to get a good desk ornament from one of the two bad cylinders once the head comes off

[@Leenre9]

Valvetronic is a very good solution for the problem of the single throttle body that limits the response time of a gasoline engine. These engines can reach their rev limit in milliseconds because of the perfectly controled amount of air each cylinder gets with just controlling the amount of lift the intake valves do as it revs up. Of course, it's complicated and if there's any problem with the system or the engine gets worn out, it can't maintane the good flow and speed of intake air and has to use the throttle body itself and reverts back to a normal gasoline engine. Usually it's pretty hard to repair the engine heads of these engines without factory technology, especially the seating of the intake valves is the most critical point of this whole thing. This makes them a pretty expensive engine to maintane.

[@jacquesc3166]

This comment should go to the top for education/awareness sake. Thank you.

[@volvo09]

Thank you! I was wondering the benefit, and not having to wait for intake vacuum to "go away" makes complete sense. I had heard the system was designed to reduce pumping losses, but that never made sense to me, because why does it matter if the intake vacuum comes from a mostly closed valve, or a mostly closed throttle body, the cylinder will be fighting the same amount of vacuum to maintain a power level.

[@bobcoats2708]

That was a lovely bonus inspection port someone created in the valve cover.

[@JCP519]

Been waiting to see an S55 for a while now! Glad you were able to find one!

[@jeffreystaley5266]

Wow! Seeing the inside of this engine was quite an experience. The variable valve timing mechanism was amazing. The crank was a work of art with those sculpted counterweights. All aluminum and beautifully machined. Now I know why the price hike for the M cars is so steep. This one might mess you up a bit because it makes many other engines look so pedestrian. Thanks for showing it to us.

[@johnparker221]

Congrats on a profitable teardown. Now for Erics homework. Once a at the end of the a video, we get to see the vehicle of the week being tore down. Once a month, I would love to see pictures of a vehicle being tore down(sequence of pictures) and see Erics pocketbook in a happy state. As the vehicle gets parted out, we get to see the nice parts, and then finally, the poor remains in the scrap bin. It would be nice to feature the tech involved in the tear down and his triumphant meal at Mickey Ds or even a steak. Just a suggestion. It would be fun too.

[@longrange1977]

So in other words, I do Scraplife Garage? I fully second this.

[@decentdan_k]

Huge fan of the channel Eric! If you come across an Audi 3.0 TFSI supercharged from 2010-2016 or so I bet theres a bunch of us who'd love to see a tear down. One of Audi's more relable motors from my understanding.

[@NickV2k9]

I second this. Would love to see an Audi 3.0 teardown

[@kristensorensen2219]

That is a nice piece of engineering! Too bad the RPM limiter failed😂😅😮 & the valves got slapped! Glad you found a winner Eric, for tonights teardown!!❤

[@jbrown7403]

Great video! I drive a F82 M4 with this S55 engine and I love it. Really cool to see this engine tear down! 🏁👍

[@darylmorse]

As an owner of a BMW with an S55 engine, I'm glad to finally see a teardown of an S55. These engines are really impressive. From the factory, they were offered with horsepower from 405 to 493, all from the same long block, with the difference being the tune. With stock internals, they are good for well over 750 HP. Considering you are a BMW guy, you should know that one of the problems with the S55 engine is a spun timing gear, which manifests itself with valve to piston contact. Unfortunately, it's too late to find out if the valve to piston contact was caused by movement of the timing gear or because of a missed shift. (You would have had to check the timing before you took it apart.) This engine is in pretty nice condition and it should easily be rebuildable.

[@jonb2437]

He said that if the timing was off only a few cylinders would have bent valves and messed up with the rockers. In this situation, valves hit pistons in all cylinders which is why he thinks it's from being over reved and not mistiming. So no it was not a spun crank hub

[@darylmorse]

@@jonb2437 I know what he said. If the timing was off and the engine was still rotating, there would have been contact in all of the cylinders. It only has to make two revolutions for all of the valves to open in all of the cylinders. He didn't check the timing, so there is no way to know if the problem was caused by a money shift or a spun crank hub. In the worst cases, spun hubs are completely lose and freely rotating on the crankshaft, so the engine cannot run, but in the "best" case, the sprocket doesn't break completely loose, causing a timing problem which generates a fault code, but no contact. There are many possibilities between the best case and the worst case.

[@Salpeteroxid]

I just spun my crank hub. E45 stage2+ custom tune. Have had it for little over 2 years. Don't think anything made contact but I'm upgrading to the Vargas splined hub and doing the chain and a lot of other stuff. Will be buying EU5 injectors and push a bit more power, aiming for 650ish and next year some turbos to get 750whp.

[@keine_ahnung_wie_der_heisst]

"only the tune", so water methanol injection in the m4 gts is just a tune?

[@joemuncie9187]

BMWs are, like their Benz cousins, very well engineered and built. Unfortunately the average BMW driver is a savage.

[@raykaufman7156]

Nice score. The rotating assembly was gorgeous.

[@stephenshort839]

Your knowledge of the many types of motors that you have is VERY IMPRESSIVE.

[@mahcooharper9577]

Well we all like carnage but it's nice to see you actually made some money out of this one! And it certainly wouldnt be the first engine to get a lick of paint and be sold as "remanufactured"...

[@johnmoore8599]

Great news! Glad it's a money maker! Thanks for the teardown and opinion on what transpired!

[@Hdaledevore]

You never disappoint, great videos keep em coming

[@aland7236]

Someone's money shift helped put Eric's kiddos through school and gave us some entertainment this evening. My old Honda Accord had a mechanical lockout for 1st when moving over a certain speed, I dont know why the same mechanism couldn't work for 2, 3, or 4.

[@presinald]

Probably to get money shifters to spend more money at the dealership and to save the cost of implementing that tbh

[@Ponykotze]

This thing is a stunner even inside, it’s engineering at its best

[@jannehokkanen8175]

Nope. LS is way better engineered. Biimer looks nice inside though.

[@bennv5909h]

20+ years ahead of and ls engine

[@GoldenCroc]

​@@jannehokkanen8175Apples to oranges, comparisons impossible since eveything targeted during development except both going into 4 wheeled vehicles, were different.

[@joe125ful]

@@GoldenCroc Excuses..no matter its I6 or V8 you can build both types well. And LS is just better maded or even JZ/RB engines if you want drag 6 cyl here.

[@GoldenCroc]

@@joe125ful No its not excuses, you just dont fully know what the engines are designed for. Its not just as simple as "make vehicle move", there are hundreds of different reasons and legislations to follow and take into account during the design process. Nothing to be ashamed of not knowing all that much about it though, most people dont know much about global engine design targets, because you need to be pretty into car industry specifics and know a lot about different markets to do so. But thats how it is. So yes, its apples to oranges, for example a LS engine would be borderline unsellable for many of the market this engine targets, because of displacment and CO2 emission based road and luxury taxes etc.

[@ChumpyChicken2]

That was awesome to watch! It looks engineered for big power. Shane the turbo’s were missing.

[@jasontroy4723]

Hey buddy you need to make up a custom oil drip tray to suit your engine stand ( wouldn't be hard and saves cleaning up crappy old oil from the floor ) . Keep up the tear downs . very educational . cheers .

[@samuelbeasonjr.3308]

It's Saturday night and I'm looking forward to this tear down and a beer.

[@erikandreassen6531]

A common rebuild problem, skim the top of the block then skim the head (if not flat) throw it back together with a thicker gasket. Then the gasket crushes during running and the one thing they should have done but didn't was to turn the tops of the pistons back to clearance.

[@Captain4life3]

soon as i heard " want to hang on to these" i said in my head Happy Birthday to the ground. Love your videos. You show me things I would never have seen. P.S I went there

[@CosmicMomentumX]

A moment of silence for the "numbers matching timing guide". Thank you.

[@encinobalboa]

That it shatters like glass does not inspire confidence.

[@jaredbawden6707]

@encinobalboa try it with a cast camshaft and see what happens. Eric has done this once too. Just dropped it....

[@AB-nu5we]

The water pump get sold already? Congrats on such a good find.

[@Blurky82]

I bet that oil pan gasket is going to live on that rack post forever now😆

[@jeffreyshepherd8488]

I love how it went from crack the cam caps, to cam the crack caps, to lets cram these off 😂 the evolution of that running gag and all of your running gags has been fantastic

[@ghettobutter]

so cool to see the inside of an engine i've spent so much time on the outside of thanks for taking the time great videoi!

[@GregOliverJr]

I love seeing the bmw and toyota engines. I found this channel by the 5vz teardown (as i have one that luckily doesn't need torn down) and been watching ever since. It would be cool to see a m54b30 (another engine i own) if you ever run. across one.

[@Kiham80]

Must be a very big engine if Eric can run across it.

[@jp2246]

23:34 score! that was impressive 👏

[@kevincurry4735]

As you read this comment have yourself a great day while watching Eric tear down this bad BMW engine.

[@robbytheremin2443]

Saying a bad BMW engine implies there are good BMW engines. *tactical eye roll

[@kevincurry4735]

🙄😆😂🤣

[@auntbarbara5576]

Thats' lime saying "drug deal gone bad", there arent any good ones 😉

[@POVwithRC]

I will 😊

[@POVwithRC]

​@@robbytheremin2443There are. Plenty. It's just they can become bad with neglect.

[@skildude]

1 minute in and I see that the Water Pump is missing. Dang, no smashed pump today

[@dehypnotizerz]

Eric, thank you very much for your teardown videos. Thanks to them I really learned a lot about engines. I've small request for you: don't you happen to have an AMG A35, 4 cylinder, 306 HP engine (or a similar one) waiting in line for the teardown? I'd like to know what do you think about such a heavily stressed engine, what to avoid and if driving it gently I can rely on such an engine. Thank you and all the best!

[@waverleyjournalise5757]

New oil and filter every 5k, drive gently until warm, and any modern engine will see you through just fine

[@dehypnotizerz]

@@waverleyjournalise5757 Thanks, bud and sorry for the late reply. I'm very gentle on cars and I frequently check whatever I can check. No dipstick, so I found a hidden, service menu: the stealership changed my oil exactly as I told them, i.e. after 5k, twice already and the last time they added 0.3 liters more than the nominal level, but with almost 6 liters of oil in the engine I believe it's more or less okay. I'm still learning the thing. A week ago I was speeding on a freeway and while braking it was dragging me to the right. It was visible on the dashboard (temps were higher, particularly in the right wheel). I quickly called the technician and the car senses the crosswind, would you believe that? Upon return, it was dragging me to the left under the braking. Electronics literally everywhere, but at least it's a gas-guzzler, not a lame EV. But aside from the cars, I'd like to wish everyone a Merry Christmas and a Happy New Year! Thank you all for all your sympathy, it's a great channel, which apparently gathers really cool folks. All the best and stay safe!

[@bennv5909h]

Eventho bmw has bad history, you gotta appreciate how advanced the engineering and serviceability is in this engine, all thoes parts that could fail but everything working together to keep it in perfect shape. True motorsport inspired

[@GoldenCroc]

Well it depends on what you mean by "history", it was mostly 2000-2010 era that were the real dark days, after and especially before that, they were considered some of the best engines out there in most metrics.

[@martinllanos4998]

This is a typical problem wjth s55 and the main problem is crank timing sprocket slipping from the friction disk. I would check send out the crank to machine shop to make sure the front shaft is not bent

[@masterSe7en77]

Omg I bought this cylinder head lol, dude I hope it works well, I looked at the valves I didn't see any bent EDIT: THE HEAD WAS GREAT IT WORKED OUT PERFECT THANK YOU, YOUR PACKAGING WAS AWESOME TOO, THANKS FOR THE BIG YELLOW AND BLACK BIN :)

[@michaelmooney1474]

Damn I love these freakin things. Takes alotta time young man. THANKS SOOOO MUCH

[@MacGyver-1]

The marks on the side of the cylinder walls correspond with the coolant passages that are drilled at the same angle between the cylinders. If I had to guess it's because the temperature differential in that area

[@m.kriddick2731]

A suggestion for Christmas, can we get a heart warming story of how you and Blue met, how long you've worked together, maybe some stories from your past. As much as you and Blue work together I'm sure I'm not the only guy who wonders about how you guys met and became coworkers...

[@user-jl7hx1zz6d]

Fun fact. The valve-tronic engines actually still need a throttle body. At its most basic concept, no throttle valve no vacuum. There are some really awesome videos that go in depth to disprove the myth of not needing a throttle body. Very cool video by the way.

[@haaseuros9789]

Well that's why they have vacuum pumps lol

[@user-jl7hx1zz6d]

@@haaseuros9789 Not enough brother it's simply an assist.

[@Nadi-Ger]

Wonderful! I'm (surely not the only one) always happy if it's not carnage or huge damage.

[@BWADaniel]

Can you please keep your eye out for a 4.7L M139 Maserati engine. I’d LOVE to see one of these get torn down. Even if you find the 4.2L, cool!

[@blanketboyactual5264]

Love these tear downs so much. They’re so satisfying!

[@timbrown9731]

Love to see you get your hands on an S65 Eric!

[@ScottJ175]

A whole series of Festivus miracles on this teardown.

[@billwood586]

Please do a video of what you do to usable parts from cleanup to storage and then sale.

[@IllusionInfusion]

Nice sound from cramming them crack caps loose.

[@jetro7349]

Crank hub probably spun, if you take off the big front center bolt on the crank the front chain sprocket/hub is held in place by nothing but the torque of that front bolt... They often spin causing the engine to go out of time. DCT's are a little more prone to this when kicking down gears. There are quite a few aftermarket fixes and it's quite expensive to have them done.

[@benmorris5046]

Exactly what I was thinking. Not an uncommon problem on these engines at all.

[@jaimearredondo4131]

I came here to say that - 100% that is what caused this

[@TML34]

Wrong. There are friction disks in addition to the crank bolt.

[@bigboost2641]

My guess too, relatively rare to slip on standard power but a lot more common on a stage 1.

[@CaptainSpadaro]

Is the crank hub that large an issue on 16-later cars?

[@Chchchopstickss]

Im getting a longblock for 2k this weekend hopefully its not bad, it was a sized intake cam. but fingers crossed. learned alot and what to look for with this video. thank you

[@AlexCapi]

12:08 that camshaft bearing ledge is used in the N52, N53, and N54 also.

[@flyer709477]

Best part of my Saturday night!!!

[@komtgoed8330]

Possible that the crank hub spinned. They do sometimes suffer with this problem. Love the channel!! All the best from holland!

[@jonb2437]

Although that can happen with this motor, when he took it a part the timing wasn't off. Spun crank hub immediately throws off the timing.

[@Skeeter69420]

Thanks for another great video to finish off my Saturday night.

[@compu85]

Hmm, neat design that you can replace the chain guides from the top.

[@kayciecarryl3366]

Ahhh, first video of the day and first coffee of the day! A great start. 👧

[@smc4229]

Spiking the chain guides is up there with the water pump toss when it comes to gags

[@BigUriel]

Early version of this engine were prone to slippage of the friction ring that holds the crank hub. A small slip can cause the engine to move out of timing but not enough to visibly bend valves. Some engines survive these failures with little to no damage, the valves may be bent enough to leak and throw up misfire codes but not enough to see with the naked eye.

[@darylmorse]

It's not just early versions of the engine. As far as I know, based on the part numbers, the design was never revised. I'm pretty sure any S55 can potentially have the problem.

[@luker3456]

This was only addressed in the s58 and can happen to any s55. Although its usually only caused by lots of power or agressive use of the kickdown function on dct cars

[@darylmorse]

@@luker3456 There is little or nothing in common between the S55 and the S58. They are completely different designs, but you are correct that this problem doesn't happen on the S58.

[@luker3456]

@darylmorse nothing in common except for the displacment, cylinder count, number of turbos, manufacturer, bore diamiter, dual vanos, valvetronic and direct injection. Infact s58 is so different that it has 0 4mm extra stroke 🤣

[@darylmorse]

​@@luker3456​You are clearly clueless about these engines. Take a look at the parts diagrams of these engines. They might have a few fasteners in common, but even that is unlikely. The B58/S58 are clean sheet designs. The camshaft drives are at opposite ends of the engine FFS. The reason why there is no crank hub problem on the x58 is because there is no crank hub!! The camshaft drive is part of the crankshaft. Get a clue before you post nonsense.

[@johnwhite2663]

Nice to see you win one. Congrats!

[@sparkyprojects]

I've owned 4 Triumph Heralds, they have light springs (you can compress them with a couple of thumbs), they were prone to Valve Bounce if revved too hard.

[@theairstig9164]

1950s rev limiter

[@terrynagle7410]

I am happy you won this engine.

[@DOCTOR_KIA]

here it is!

[@billhyde2303]

The engine gods re smiling on you today!

[@exquisiteart6478]

The God's have answered me, I was looking for an S55 engine teardown literally yesterday 😂😂😂

[@44hawk28]

The aluminum bolts should not necessarily be one-time use. The reason they have so many bolts is because the torque spec is fairly light. As for that sludge you saw on the engine it looks like somebody had run the car a little hard, I don't know why they would do that, but that can cause some scaling in the turbo system and then it draws it back out of it and deposits it in the engine. Otherwise somebody at least one time went with an extended oil change interval. I don't believe that happened, but I have noticed that there are people who actually put devices on their turbocharged engines so that when they shut it off it'll sit and idle and allow the turbochargers to cool down before it shuts the engine off.

[@shaun9067]

Best engine this year for parts

[@smartyy86]

4yi the valvetronic solves a problem zhat does not really exist anymore. it was introduced in the time where BMW tried to maximally optimize the naturally aspirated engine (which they did with this) to remove 2 key fuel inefficiencies. one is the losses due to reduced ambient pressure in the intake manifold because of the throttle-body, and the second reason was it removes one of the key ineffiecies in the adiabatic compression stage while not at full throttle by a decent amount. all naturally aspirated engines with 6 speed are practically always operating at partial throttle, which this helped. one of the reasons the N62B48 is so well established and even produced today. For the S engines it allows to generate boost up to the intake valves, because they are the only thing limiting the airflow, so the response of the throttle is absolutely mental for a turbocharged engine.

[@chrissavage5966]

Many years back in the UK, there was a company that sold rebuilt engines called 'Gold Seal'. Yep, the engines came with an overall (and I mean overall) coat of gold paint. Oddly, they never seemed to last very long..... Rattle-can rebuilds don;t seem to last.

[@bilphil74]

Still would like to see a 1.8 from a 2016 Chevy Sonic, and a 2.4 SRT4 that came in the 2003 Chrysler PT Cruiser GT with the aluminum intake

[@TheNationalTrails]

"Big Block" for Importa! Nice to see.

[@702Wolfi]

Bearings look like owners liked giving it full beans when the engine/oil was cold.

[@marathoner43]

Another great video. Thanks for my Saturday night entertainment.

[@DannysGarage]

What most likely happened here is the crank hub slipped and messed up the timing. With the Valvetronic and Vanos systems, the intake valves survive because the engine can correct for the timing on the intake side, so the exhaust side takes the brunt of the damage. This is an extremely common problem with the S55, and I've seen stock engines with this issue. It's a design flaw from using the same timing system as the N55 and N20 where it's just a friction fit on the crank hub- while it works fine for those engines, it's not enough for the S55. The proper fix for this is to pin the crank hub so that there's no way for it to slip. A buddy of mine runs a turbo BMW performance shop here in the Phoenix area and they've done a few dozen crank hub jobs for people with the F8x M3/M4.

[@bretttully2771]

If I had gotten a broken bolt out that easy I would’ve stopped on the way home and bought a lottery ticket. My guess on the gunk in the oil pan is soot or carbon. Had a Cummins spin a bearing because of enough of that gunk plugged the oil pickup. But if you rubbed it between your fingers it just disintegrated. Found out the turbo was leaking oil internally and probably the reason for soot buildup, but nothing ever confirmed.

[@erickinkhorst555]

Give me a smallblock any day. Great video as usual.

[@SvenKleer]

Actually at BMW garages, there is a tool to get the injectors out and at the same time measure if they are in there "too tight" cause theoretically they could be damaged after disassembly... So that doesn't look that bad actually

[@vincenthardman7691]

Watching this video really gave me the impression you'd done this before. :-) Thanks for the video.

[@TroyRosenbaugh]

Wonder if you twisted top of head bolts on a few of em...

[@JeffSchohn]

Love the Snack Pack on the shelf in the back round. 😂😂😂

[@timvanlandingham1927]

So, why were the valves contacting the pistons?

[@18Macallan]

Thank you Eric!👍

[@invertedv12powerhouse77]

I kinda wanna buy blown engines now for cheap just to take them apart for fun, and rebuild them if worth it. I want to add a tip as well, but giving a few taps with a mallet or brass punch on the heads of aluminium bolts can help prevent having one shear off. Especially when they are siezed bolts that take lots of heat stress. The next thing is instead of using the electric impact, i break the torque slightly on each bolt. If one is harder than the others on an aluminium bolt especially, I will tap it some more and break the torque very slowly and in smooth motions. Hard snappy motions shear aluminium bolts all the time when they are siezed. Penetration fluid for bolts as well helps a ton.

[@beyondmiddleagedman7240]

That "M" wear pattern is the Speed Racer logo.

[@davidstuck2866]

I know that you know this. but, it might be beneficial for you to put some parts solvent in the ports of the valves that you suspect are or may be bent (and show the results). that would give an idea to anyone who may be thinking about buying the head. if they do leak, he or she will KNOW that they will need to replace the valves. and if they do not leak, then there is at least a chance that they might be salvageable. I know that if I was looking for a head, that is something I would want to know.

[@steveblackbird]

Great teardown, and great shot with the oil pan gasket hahahaha

[@paulphillippe5862]

Excellent video!

[@chrisbradley3224]

Crank hub spun on this engine maybe initially? When the diamond friction disc that holds the cam drive sprocket to the oil pump sprocket and crank snout fails the sprocket slips and timing is lost. It's the only common S55 failure mode. It only slips a bit usually though.

[@DeltaV-Garage]

I was thinking the crank hub spun as well. S55's are known for doing that with high power mods.

[@anthonyt4981]

he said the engine wasn't out of timing

[@ouch1011]

The *S* in a BMW engine means it is *S* ubstantially less reliable than the M or N version of the engine. That’s bad news for the notoriously unreliable N55. I’ve said it before and I’ll say it again, I’ve _never_ seen one of those heat tabs that was still intact. They always melt as soon as the engine is brought up to normal temperature. They are not an overheat indicator, more like a “this engine was started” indicator. What I’ve been told is Valvetronic is meant to improve engine efficiency by reducing pumping losses, because it takes a fair bit of energy to pull the piston down against a vacuum. The problem with that theory is that you’re still pulling the piston down against a vacuum whether the restriction is being caused by a throttle plate or an intake valve that barely opens. Another possibility is that they’re trying to improve fuel atomization by increasing air velocity past the value with a small amount of valve lift, but I wouldn’t think that would really be an issue with a direct injection engine.

[@GoldenCroc]

N55 notoriously unreliable? I guess it all depends on the perspective you got.... Anyway, what can be said is valvetronic seemingly really does make a big difference in efficency.

[@dylanoppeneer2354]

the n55 is very reliable if well maintained

[@peterhart1966]

Love the channel, watched a kazillion IDC videos and never been disappointed, but after watching so many videos I just realized I’d never hit the subscribe button! Apologies! Big fan and SUBSCRIBER

[@scottallberry6713]

Would love an episode with you and Derrick from vice grip garage