500HP Miata Breaks A Record & Breaks Itself! (100-200km/h)

[@carracuda3920]

How fast was that 1/4 mile pull looking to be?

[@TheCarPassionChannel]

Unfortunately using flatshift is a bit harder on the clutch, which caused it to slip. It was only a 12.69 @ 126mph, but, for reference the 100-200km/h was only 6.71 on that run, so it's basically a throw away. The car should have no issue breaking the 130mph barrier in the quarter assuming the clutch holds on.

[@TheJohnb35711]

@@TheCarPassionChannel adjusting either the clutch grab point to be a bit lower or the position of the clutch switch could help it not to slip with FFS

[@TheCarPassionChannel]

@@TheJohnb35711 Most likely yes, but I've had it slip a couple times even just rolling into full boost at mid RPM. I believe the torque rating it 510lb-ft, and if that's at the crank, the motor is producing slightly more than that. I'm thinking about just upgrading the pressure plate

[@TheJohnb35711]

@@TheCarPassionChannel seems like a good call with everything apart already. i was debating saying anything since you are so methodological with all this stuff

[@removeableskull7446]

Exhaust leak at the manifold ? Loose crank pulley ?

[@CashedOutCars]

Thank you Mexico for providing these proving grounds

[@38tech]

It tis the way when you are forging new territory. If it's not the rod bearing and the noise is coming from upfront, maybe the oil pump?

[@mellopelas2857]

As a Mexican, your welcome :)

[@andyanderson7712]

Is there no speed limit in Mexico? Seems that youre setting yourself up driving like that in a country where corruption is so rampant.

[@38tech]

@@andyanderson7712 yeah def DONT get pulled over in Mexico. Unless you have a wad of cash.

[@davidbarlowjr7583]

"-And everything went okay until!... Nah just kidding." BOYYYYY You had me lol

[@jptperformance]

I’m going with thrust bearing failure. Highly unlikely to be rod or crank bearing since the car made it home with out a problem

[@johnmoscrop9253]

That was my thought as well 👍

[@hewbambam]

If it were a thrust bearing it would change when the clutch were pushed in

[@jptperformance]

@@hewbambam not necessarily since the clutch was acting strange and it does not make noise when the clutch is pressed the rear thrust washer would be the one that went not the front See if the front went you would be spot on correct saying extra noise would be apparent but if the rear goes when you press the clutch it would fix the sloppy tolerance and press on the front thrust washer But it’s all speculation until it’s taken apart and the problem is found

[@Grumpini]

19:47 Crank walk/thrust bearing

[@R3IMU]

Good guess Senjougahara san. That would also explain the "clutch slip"...

[@sjorsangevare]

@@R3IMU @TheCarPassionChannel I dont know if you get notifications from replies to comments but this man makes a good point

[@J3n555]

My guess too!

[@kitastan]

@@R3IMU why it would explain clutch slip? I would say rather the effect would be no clutch disengagement rather than slip.

[@sjorsangevare]

@@kitastan it depends on which way the crank walks right? If it goes forward the clutch will slip

[@kitastan]

On the last pull you can clearly hear increased noise on 4th gear. I don't think it is rod knock, more like main bearing knock (I had one failed me last year and it was similar noise). It may be also piston slap but I'm more on the main bearing problem. Funny think is that when main bearing spoon oil pressure dropped only by a little... Till the end I was hoping it will be simple fix 😔

[@Nasonix2]

If his main bearings were gone, he'd have little to no oil pressure. He does have upgraded oil pump and if it's shimmed, putting out more oil pressure flow/psi than factory then maybe he'd still have some oil pressure but you'd still see a noticeable change. It would likely be half as much as before or worst.

[@kitastan]

@@Nasonix2 like I said I had spun main bearing and the oil pressure were little lower but was still there. It may be also bend rod. We will see when he drop the oil pan.

[@ethownzbh]

My miata is still sitting after I threw a rod bearing years ago and then swapped in an engine that had no compression in one cylinder lol so I feel this pain to some degree.

[@accordv6er]

Lol me too!! Except I have since swapped that* engine, for another ... That has a bad HG leak into the cooling system. About to dig up a Gen III hemi and say f it. Already did a standalone this last go round so not hard to swap at this point

[@ethancargile1264]

Yup! Did a 1.8 swap to replace a nuked 1.6 only to realize that the head was trash and low compression on cylinder 4. Finally found a good motor at a good price after months of looking. You’ve got this homie

[@bandwagon240]

Kinda sounds like crank walk to me. If you put the trans back in, fire it up and have someone depress the clutch while you watch the crank pulley. This is always how we did it in DSM times.

[@thetuber705]

or just push/pull on the flywheel.

[@blandflatland8915]

Bought a 1990 Miata and fixing all kinds of things and your videos helped me immensely in tackling the timing belt/loctite fix. I’m now dreading pulling the trans to fix a rear seal oil leak. Lol you made pulling the trans look so easy here!

[@mxwizzard]

The Trans on the miata is easy it takes about 3 hrs to pull out replace the clutch and rear main seal and put it back together

[@hittman8592]

I'm going with crank walk/thrust bearing.

[@willmaddox1986]

Sounds like thrust bearing too me. Might be worth tapering in that 30psi 😂

[@acentricity]

A couple weeks ago I was doing pulls when I lost a bit of power and my exhaust got louder. I figured the downpipe vband got loose from the heat. I tightened it, but the power loss and noise didn't go away. Checked everything I could, compression, oil, timing, ect and second guessing myself on all of it. I was racking my head trying to figure it out until I happened to notice a bolt was missing off the back of my turbo. I have a ebay special t3/t4 internal waste gate with the 5-bolt pattern that turns into a 3" v-band. Apparently when they drilled the bolt holes, they went all the way through the housing. The bolt must've gotten hot and fell out which allowed the exhaust to bypass the turbine and the O2 sensor to misread. One trip to Ace Hardware and everything was back to normal. It doesn't sound like that's your problem, but here's to hoping your issue is an uncommon stupid simple to fix too.

[@Flavbean]

Man, I wish I lived next to a guy like you. So much Miata knowledge. Thank you for the great content 🙏 😀

[@ciao716]

Amazing diagnostic and your explanation through it. Looking forward for more in depth video and when you'll find out what has happened :D

[@TheCarPassionChannel]

I was hoping someone would appreciate it and that it wasn't too boring!

[@elwindewitte]

@@TheCarPassionChannelit's always super interesting and honestly entertaining when you breakdown how you go about finding problems and fixing them! Hoping it's somewhat fixable, but at least she had a good run! Man those pulls were awesome!

[@elwindewitte]

I should add that these more in-depth videos are exactly what inspired me to work on my own car and do (and learn) maintenance myself. If you go little by little you'll get there. Really happy to have been doing a lot the work myself ever since owning my Miata! Forever grateful for that, thanks Greg!

[@ghostpunkkilla]

The way we used to diagnose rod knock was while the engine is running pull a plug wire on each cylinder and see of the noise gets quieter. Obviously you would cycle this if you don't hear it change, and it'll be a little different since you have COP. But perhaps you can just kill each cylinder via the tuner.

[@Red2l16v]

This is perfect for rod knock. I was going to suggest it but an oil analysis will tell the story. Along with a check of endplay. You can do that with the trans off with a pry bar.

[@MaxSpeedMike]

Thank you for the thorough diagnostics and explanations

[@kolopiom_og]

Aw hell yea, miata monday Edit: big sad on the engine issues, hopefully it turns out to be something easy to diagnose and fix

[@Girz0r]

Just thinking how beneficial this video is to all the new people wanting to build turbo miats. Great Video!

[@BigIsleJ]

I’m sure whatever it ends up being, you’ll figure it out and share the knowledge. Mahalo for all you do!

[@jimmy4993]

Rod Bearings, main Bearings or thrust Bearing. Either way I think you're up for a rebuild mate. I was in Mexico the other day too....but the one in Australia 🇦🇺

[@TheCarPassionChannel]

Lmaooo the Australian Mexico is another hot spot

[@elijahbakker1513]

I built the same motor you did and blew it up instantly because I vapor blasted the head and the media bonded with the residual oil 😭 feel ya man, keep pushing. I built an nb1 motor in another 6 months and now she's running again! Keep it up, it's all worth it in the end!

[@irebird]

Check for bent rods, if one is shorter the sound could be from the piston hitting the crank. But with drive back home I would expect it to self clearance.

[@TheWhoever811]

Yup, this. But compression on that cylinder might be a bit different if that was the case. I bent a rod one time and it sounded just like this. It got louder and louder on the 2 mile drive home though. It was bending the rod more and more as it was put under load climbing hills and stuff. The crankshaft was eating through the piston and almost made it through to the wrist pin.

[@91ludesit]

It sounds like either thrust clearance or main bearing failure. This man out here finding the limits of the block.

[@tickandslug]

Hell yeah. Love these testing videos, Greg.

[@8JustARegularGuy8]

The worst things always happen to the best people! Great explanation in the video for each diagnostic test you did and why. To me, like some others have said, sounds like main bearings or crank walk. It gives a very similar sound to rod knock, but obviously every test you've done has exhausted that possibility. The only way I know to test for main bearings is by taking everything apart and visually inspecting them unfortunately. Every video that comes out with the red car is always exciting. Seeing this car progress over the years really brings me, and I'm sure a lot of other people motivation. Keep up the great work, keep your head up, and keep the amazing content coming. Sometimes the best things you can do is walk away from something, sleep on it, and start again with a clear mind.

[@wills_garage335]

I'm surprised you didn't check endplay, although when my nb had a thrust bearing failure it still idled smooth, the crank moved under boost and I would lose crank sensor sync

[@dreednlb]

Sucks that this happened but this makes for such good content.

[@tubejorrit]

K24 build? :p

[@madmiata1887]

Did you try the bottom end isolation test?! Remove the top end. unplug fuel pump relay, plug oil ports, crank bottom end and listen for noise! I just made that up, but might help idk. GL homie. That doesn't not sound like rod knock or valve train. I like the crank walk theories, I just never heard crank walk before.

[@dannym7759]

My condolences to the bottom end dear sir. Definitely sounds like a bottom end bearing issue. Either way, considering the amount of power you were running and it lasted 15k miles consider it a good time. The next build will be even stronger. 🙌🏼

[@TMonist]

Dude, we are here for the good times and the bad times. When you are troubleshooting, we are all troubleshooting. You have me on the edge of my seat. I feel like we've been into this journey together. Even though you are doing all the work 😆✌️

[@craig7111]

Ah man, such a bummer! Thanks for showing us your diagnostic process.

[@michaelswitzer9220]

Ugh, heartbreaker dude. I’ll keep tuning in, curious to see what you find in that engine. Sounds like a rod on my crappy phone speaker, so obviously my opinion is valid. Haha. Keep up the quality content. You’ve probably saved someone from hours of brutal work.

[@SSHAMR0Ckk]

check for end play/crank walk, thats what took out my first built motor, crank was contacting the main caps and wearing it down

[@ppppsssshhhh71]

at least you still got compression. Sounds like a bearing. maybe thrust bearings like I seen below. I would just give the old gal a nice refresh. 15k hard miles, there isn't any shame, and its definitely part of the game. great video as always.

[@robertmetcalf3380]

I think it could be with the hamonic balancer itself or the sensor plate behind it. I had on a truck I owned the damn bolt kept coming loose and it sounded like that.

[@ferox1183]

My guess is the thrust bearing because I heard a similar noise a few months ago. When we disassembled a engine we saw significant axial movement and high wear on the thrust bearing.

[@mtbiata]

My NB2 is also making a knocking noise now, but it doesn't sound like your engine. Mine only happens above ~2k rpm, and it gets louder as the engine warms up. I'm gonna check valve lash right now to see what's up, but I'm really hoping its not a bearing in the bottom end :( I hope Lil' Red recovers fast Greg! You got this.

[@mikescherrer4923]

timing tensioner?

[@mtbiata]

@@mikescherrer4923 I’m literally looking at that right now lol. The timing belt is definitely looser than it should be. So I’m trying to loosen up the tensioner bolt to re-tension the belt but I just can’t get that bolt loose. I can’t get a wrench on it enough to loosen it. I also just checked my lash and only 4 of the 16 valves are in spec 🤦‍♂️😭

[@GE3KSPDMOTORSPORTS]

Epic build and amazing troubleshooting. I hope we're all wrong and it's a simple fix. Felt that pain throughout the video. Whatever you do next will be faster and cooler, with this nugget or another, looking forward to that!

[@ricepony33]

Maybe try some Thicc Lucas oil :) But seriously the crank movement seems the most likely.

[@ruidiasbraga]

This channel is underrated

[@thememeyata6837]

Best of luck problem solving this one, hate this happened so soon. But tis the game of high horsepower.

[@Drumheros]

I had a similar noise from not tightening water pump pulley bolts enough. I think you would've torqued those down but is there a chance they came loose? Also worth checking any other pulley bolts like crank pulley.

[@blackshine007]

I once had what I thought was a knock coming from my engine. I waited a couple of weeks before I could replace the rod bearings. Started the car and the noise was still there. Removed the serpentine belt and the noise went away. Turned out the bearings in the alternator failed. At least it had a new set of rod bearings 🤣

[@of_lion22]

Though rather unfortunate, glad the car didn't have a catastrophic failure like the 1.6 My guess, like others have said, Worn thrust bearing. I'd imagine a very stiff pressure plate would increase thrust loads. To pull out an old DSM meme; "See Crank? See Crank Walk Walk Crank! Walk!"

[@jeanboy9108]

2.0 Fe3 swap. Mazda's version of the 4G63. Basically a big block BP. Holds 400hp with stock internals.

[@dirtperson4221slash2]

Congrats on breaking your record! You are a madman.. I wouldn't be surprised if Greg still calculates how much he can eat each day to put maximum funding to each build/#2$jR .. awesome video, thank you

[@christianzinn7636]

WOW! After suffering withdraw it sure was great to see a new post, but my heart broke with yours when the engine went south. I am so very sorry to see this and my heart goes out to you!!! You are a lot smarted then this OG, so I can't give any bright ideas other than the crank. Do you want to pull the oil pan off and give it a look??? Best to you,

[@poseidonasas]

It could hopefully be a main bearing issue. Also it was induced when selecting the 4th gear by the time the boost raised to 30 psi causing the engine to produce some serious amount of torque. Also the thrust bearing could be the culprit since the noise was introduced at high boost/torque conditions

[@chrisg998]

Love ya boi, good luck with the motor I’m really pulling for you (in my ND)

[@kristiansvensson4965]

Thank you Greg for all the great videos. I have learned a lot from these over the years. Hope you will find the problem!

[@nehok]

Sorry to see see your troubles Greg! If worst come to worst hopefuly kpower will hook you up with some k24z3 goodies! On anther note boy she was popping in those runs.

[@miatatogo9800]

I had some art of this sound on my stock MX5 1.8 in my case it comes from the 3 bolts fot the whaterpump wheel they where losen.

[@camaro69blk]

Probably the main bearing I'd say. When my main bearings went, the car had a weird vibration and sounded a bit different as well. Especially under slight load, it was noticeable. Unless it's your oil pump about to fail but I doubt it.

[@Nasonix2]

He'd have a noticeable drop in oil pressure if it was main bearing

[@camaro69blk]

@@Nasonix2 Maybe. Mine was not very noticeable if at all. And it was all the main bearings that were worn. Not spun though.

[@NickPahls]

Maybe bent rod? Piston hitting the crank counter weights

[@WIll52561]

I'm going with partially spun main bearing or thrust bearing issue. Super sucks, I built mine after seeing you start the vvt build. About to start the 3rd race season on the motor.

[@robclarke390]

Feel for you man! Although it's shit, this video was absolutely sick. Loved the in depth problem solving. If anyone can find the issue, it will be you dude.

[@haufperformance]

Clutch fork pivot ball popped out then when you disengage the clutch causing extreme amount of pressure to the thrush washer causing thrush washer to go out and your crank to walk.? Idk but it does sound like crank walk

[@sonofthehill1320]

Glad you made it home.

[@chrisdeli7547]

if the compression is right it might be thrust bearing 6puck clutches have big impact to the thrust pull and push the flywheel to check for play same thing you did with the rods. another thing if it comes from the nose you might have oil pump issue

[@lynam100]

Have you drained the oil and inspected it for metal? How about cutting open the oil filter and inspecting that? Or inspecting the screen for the vvt ocv?

[@Fosgen]

Thrust bearings, order new, most expensive, highest quality you can find, and send main crank for balance and polishing.

[@nermalsnert5503]

Can you take the plugs back out and measure piston travel? Bent rod?

[@z_855turboR]

I believe when shifted in fourth, the noise could already be heard..any sign of overboost in logs? If oil press is all good, maybe rod bent, or crankshaft play/thrust bearing issue. Once had a case of a broken thrust bearing (don't remember what car) removed serpentine belt, stuck a pry bar behind harmonic balancer and there was movement. Removing oil pan would tell more either way..

[@miatamadness9535]

Some good points, but I just want to point out if a rod was bent you'd lose some compression In the affected cylinder

[@z_855turboR]

@@miatamadness9535 I see what you mean, there are many cases of bent rod, but the piston is very slightly lower for it to care, so the engine starts and runs fine with normal oil press, except for the noise. In my case the small end of a rod was kissing the crank.. Should add my rod did not bend to banana shape, but to the side, like small end was offset to big end, if that makes sense (eng. not my mother language)

[@kinglouiesshed8995]

Could it be the front crank bearing ? Or the fluid damper that seen better days and Is throwing the crank out of balance?

[@jobsjobbed5125]

Really enjoyed this one. Chasing faults are the most interesting 👍

[@Nitrocity7151]

I would look at the thrust washers, if somehow they were to get out of their spot or start spinning I bet it would make a hell of a noise on the crank but your rod bearings would stay in place, you might be able to check play by moving the crank forwards and backwards but no guarantees on that. Next up I'd check out your oil pump. Since to say the sound is coming from near the nose of the crank. There's also main bearings like others have been saying

[@imboredadr]

Stretched exhaust studs/pulled the exhaust studs out of the head is my guess. That happened to my on my 99. It sounded just like this, idled fine but exhaust was loud/had a metal rattling sound. I ended up needing to helicoil 4 or 5 of the exhaust studs and the rest were able to be tightened back down.

[@reyes1987]

I'm in the rebuild stage. Mine ate an exhaust valve. Sorry to hear about your motor man.

[@peterbetting9345]

the timingbeltcover down at the crank pulley with the numbers on it sometimes breaks due to imens heat or whatever and if its loose the timing plate hits it so the tooth of the timing plate make this weird noise at first I thougth oops vvt gone but yea the I remembered my cover was loose once and it made the exact same noise so 🙈 definitly check that

[@esercitatolorenzo]

Disconnect the accessory belts and run it to see if it's something with those. Any debris in the oil/inside the oil filter?

[@TheCarPassionChannel]

I did try that although didn't film it. Unfortunately no change in the sound

[@MrSprintcat]

Don't forget to check crankshaft end play

[@kalebzweigle9750]

Wondering if the crank could have warped/moved enough to maybe spin or damage a main bearing? Maybe a main could’ve been compromised by dropping a thrust bearing? Maybe it’s as “simple” as a chipped oil pump gear. Anything’s possible I guess

[@guidosaur7506]

My turbo manifold started cracking again and I'm about ready to give up and keep the standalone but put stock headers back on lol

[@lander917]

Check your alternator, my scion made the same noise

[@nicholasfabulous]

A heavy duty clutch puts a lot of load on those trust washers jafro spoke about it in his earlier videos

[@maneki9neko]

Agreed. The worst is at startup when the oil pressure has not developed. A lot of people start in neutral with the clutch engaged to prevent this. This requires that the clutch switch be defeated in some way.

[@Progamer618]

Sounds a bit like crankshaft bearing, rodbearing would be a bit less regular knock when reving.

[@TheBaconAgent212]

How’s the oil pressure Could also be a main

[@maneki9neko]

Agreed. Bad bearings do not hold pressure well.

[@setharcher5869]

I'm thinking oil pump. Sorry to see this for you man. I know the sinking feeling when sounds start. How did the oil look?

[@maneki9neko]

Yes. Dropping the oil through a strainer only takes a few minutes. I would want to know if there were chips in the strainer, or glitter in the oil.

[@cigie4575]

I think it’s the valves man. Since the timing belt was loose I bet it crapped up the valves somehow. One time after replacing my head gasket I tried to scape some carbon off the valves and when I did they stopped sealing properly and suddenly there was a huge loud noise that sounded like it was coming out of the exhaust side of the head and it was a terrible raspy noise. Didn’t want to fool with valves so I bought a new head slapped it on and the problem went away

[@tadascerniauskas6919]

If a sound is coming from crank pulley area could it be a oil pump? Gears making noise. I asume pressure is ok so no shatered gears but easy to take it and check if you havent yet.. hoping its not a bottom end!

[@cedricbeck5446]

Check thrust and see if there is back and fourth play in crank

[@maneki9neko]

Easy job with either shims or a dial indicator to measure.

[@bparsons711]

Can you make a VVT actuator rebuild video?? From what I have read online, its almost impossible to service them!

[@TheCarPassionChannel]

After fully disassembling mine, I don't know why people say they're impossible to put back together. And I'm not trying to sound like some kind of pro, the parts are very simple, nothing spring loaded/pre loaded, etc. I will definitely make a video on it!

[@jiltedgaijin9320]

Could it be a bent rod hitting on the wall of the cylinder? Or has on of the piston pins let go so there’s some movement at the top? Just throwing my idea in the ring. Hope you find it nice and quick and get the car back on the road. It sounded immense when you were spooling it up through the gears.

[@kyletice811]

Can you check thrust easily? Maybe wiped the thrust bearing out?

[@maneki9neko]

The usual way is with a dial indicator, mounted to the block, and the plunger contacting something connected to the crank. And you push and pull the crank. I would want to know the depth of the travel.

[@cyclingbutterbean]

Muffler bearings ? Blinker fluid? Loose nut behind the wheel? I will be interested in what you find. Sorry for your misfortune. It is a monster motor and like you said it has made a ton of power its whole life. Maybe it just be done. Thanks for sharing Professor Peters.

[@soccerman0021981]

Did you ever drain the oil to check for shimmer?

[@JupiterxBlues]

You can drop your 60-120 further if you reduce drag. Full flat underbody does wonders.

[@kevinstewart9087]

Could it be an issue with thrust bearings on the crankshaft? I would maybe check the end play at the harmonic balancer. @thecarpassionchannel

[@hewbambam]

The trigger wheel could be touching the cam belt cover

[@someoneelse2106]

I think it may be the pilot bearing. Since it was not really pressed fit, it may have grenaded.

[@TheCarPassionChannel]

I think you're referring to my old twin disc setup where the pilot bearing didn't fit right. Fortunately that is long gone and the current setup does not have that issue

[@str8slayn1]

Ol Daddy Gorg blows his 1.8 up again. One day he will realize the error of his ways and come back to the path of the 1.6. Gobbless

[@nsalcedo22]

I had my timing skip a tooth once, sounded similar. I didn't tighten the belt correctly.

[@ConGie]

Some other folk have already suggested it, but maybe removing the oil pan and taking a gander there might shed some light on the problem?

[@802Garage]

Quick question. Why are you running Copper AKA Nickel plugs? Iridium and now Ruthenium are better for performance in every metric AFAIK. Even Platinum have benefits over Nickel. I know there can be good reasons and of course there is a price difference, but Nickel plugs are essentially old tech. Big bummer about the engine! Doesn't really sound rod knockey. Only other thing I can think of is maybe a wrist pin issue? Not even sure when or how those happen, but hey just tossing something out there. Possibly a piston skirt damaged so you are getting piston slap? Hope it's nothing too bad!

[@nissan_s14_]

I'm not a specialist at all but i had some weird noises when my downpipe came loose because one bolt was missing. Maybe the turbo is not completely tight to the manifold or so. But in my case it was only hearable when the exhaust was cold. when it was warm, the sound wasnt that intense.

[@SpoolinMP5]

I have a FS Mazda 2.0L engine and I have heard that sound before from bent rods due to bad fuel/ too much IGN advance. Anyway, I saw the whole video and the A/F ratios are a step too high for my comfort. I prefer to loose some power due to too rich ratios. What is your oil pressure?

[@TheAdatto]

When swapping all nuts and bolts to stainless ones on my 3200gt apparently 1 fell between my timing belt and it skipped 1 tooth. ( 2 on both camshafts because those have twice as much teeth) took me weeks to find. You checked the timing? I think you will have to pull the engine out again 😞 are there parts to make the crank or bearings much stronger? It's a weak point on my car when you have a manual. Every time you press the clutch you basically overload the axial crank bearings. (Every traffic light i put it in neutral and i wait until the engine warmed up a little before driving. And i NEVER press the clutch while starting) my mx5 turbo blew itself up (electronically) because of a bad ground. Rip me221 and tons of other things.

[@endicuddy]

Check for in and out crank play

[@ruzzzlan]

My miata is also running loud for no reason. (Replaced the entire exhaust with a stock one, still the same loudness). I wish I could recoomend something but instead im waiting patiently for you to provide some insight because I've checked over everything (to the best of my abilities) and brought it to many mechanicts, none could find a reason or explain why the engine sounds loud

[@brendangallagher8292]

Crank main bearing or really lucky/unlucky broke crank shaft or shattered oil pump.

[@VictorMPR]

Sorry to see this. With headphones, the engine didn’t sound very healthy way before that last pull. I hope you figure it out and it can be repaired relatively easily. How easy is it to drop de oil pan? Can you access the main bearings with the engine in the car?