Solved - bad engine noise!!

Stevehose

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Well, that sucks. Steve, I recently discovered a similar noise on an '02 which turned out to be a worn main crank thrust bearing. I posted on the 2002 FAQ a few months ago with pictures. You can easily get a preview (before disassembling anything) of that by eyeballing the crank axial play. Mine was like 1/8-3/16" when it should be nearly imperceptible by eye.
Wow that’s a lot of play! Duly noted to check, thanks.
 

tferrer

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The news from the front is not super encouraging - my 2002 Tii owning brother in law and our friend who is a long time BMW mechanic came over to have a listen and we've come to the conclusion that the very disconcerting clanking noise sounds low in the block so we shut it down. I didn't get a video in time. It would not make the noise at idle but slightly off idle it kicks in and isn't pretty. We did it with the clutch in and out which made no difference. So the next step is to drop the oil pan gasket (I hate this job) and see if there is a horror show in the bottom half. My garage is not much bigger than the car so not a lot of room to do this.

We agree that the engine is likely coming out, so hopefully in a year or so I'll be back on the road as I don't have a lot of time on my hands yet I want to do this myself because I've always wanted to rebuild an engine. I'll continue this thread all the way to completion be it a total rebuild or otherwise. The cylinder head that I got from Don is in great shape so I won't have to mess with that. If I do a rebuild it's getting 10:1 pistons and anything else you all suggest (already has a Schrick cam). That's all for now, thanks for the suggestions!
Well, IF you do need to rebuild, then you have lots of expertise here. Just find a great machine shop that you can depend on and that in a perfect world, knows M30's. I bought my e-type and discovered it had a rod-knock on the initial drive home so it's not the end of the world but it is quite a bummer...
 

Stevehose

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Well, IF you do need to rebuild, then you have lots of expertise here. Just find a great machine shop that you can depend on and that in a perfect world, knows M30's. I bought my e-type and discovered it had a rod-knock on the initial drive home so it's not the end of the world but it is quite a bummer...
Yes, the members here make up quite a brain trust and I certainly will be asking for counsel. Fortunately in my area there are a couple old school machine shops around. I am fascinated by machine shops, but I digress. It's all part of the vintage car experience for me - drive it as often as possible, then it will tell you when it's time to take it off the road for a while and rejuvenate it. New jack stands are on the way.
 

HB Chris

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Steve, If you pull the motor I was able to pull mine without removing the hood (I hate removing from underneath unless you have a lift). I removed the passenger side wheel, lowered it down and lifted from that side after removing radiator, water pump and trans. Sounds like you don’t have much room though.
 

Markos

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Steve, If you pull the motor I was able to pull mine without removing the hood (I hate removing from underneath unless you have a lift). I removed the passenger side wheel, lowered it down and lifted from that side after removing radiator, water pump and trans. Sounds like you don’t have much room though.

Nice!

Might be tricky to mount up, but when my buddy and I dropped his new (admittedly tiny) rotary engine, we used a pivot tool. You just crank on the bolt and adjusts the engine angle, and can tweak as you go. Pretty nifty. Fortunately we have an ongoing tool exchange. :D

Yes that is indeed a Getrag BMW six speed DSG:
53EF0A7B-8151-41B1-9D5D-1C58C8E8A684.jpeg


Edit - Link:
 

Stevehose

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Steve, If you pull the motor I was able to pull mine without removing the hood (I hate removing from underneath unless you have a lift). I removed the passenger side wheel, lowered it down and lifted from that side after removing radiator, water pump and trans. Sounds like you don’t have much room though.
Yes that would be challenging, I think the hood will come off in that scenario. This would give me more room to do all the scope creep side projects - touch up paint, cleaning etc. I’d also like to do a better job hiding the ac hoses. New clutch and release/pilot bearings…
 

boonies

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Yes that would be challenging, I think the hood will come off in that scenario. This would give me more room to do all the scope creep side projects - touch up paint, cleaning etc. I’d also like to do a better job hiding the ac hoses. New clutch and release/pilot bearings…
Seeing your past projects there is little doubt that it will be a well done project and will have some nice improvements. Still sorry to see you go through this though.
 

HB Chris

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Yes that would be challenging, I think the hood will come off in that scenario. This would give me more room to do all the scope creep side projects - touch up paint, cleaning etc. I’d also like to do a better job hiding the ac hoses. New clutch and release/pilot bearings…
Then I would mark and then undo the bolts behind the grille, much less to adjust when it goes back on.
 

zinz

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It’s good you are here, Ray; we need another live-wire. Steve was missing you and the NOLA days, Im sure.
 

Stevehose

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I removed the oil pan today, I've done this a few times and now have the process down so I don't go apoplectic when doing it any more. Anyway, nothing obvious that looks out of the ordinary. No up and down play on the rods, nuts are tight. There is a slight sliding movement of the rod along the crank bearing and also along the wrist pin-not loose but it does move side to side, I ASSume this is normal? No foreign objects found in the oil pan, and very minimal metal fur on the magnetic drain plug. Engine looks ok when rotating by hand so I am not sure where too look next, but I'm tired so will get back under the car tomorrow. Here's the sliding play of the rod ends, each cylinder is the same, any ideas on where to look next?

 

Dick Steinkamp

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The Blue Book doesn't list a spec for con rod big end side to side (thrust) play. They just list the radial play which is the internal bearing clearance (crank journal to bearing shell)

IMG_9087.JPG


There should be an official spec for thrust clearance and perhaps one of the M30 engine builders here have it.

Here's how to measure it....


In the case of the video example, it's a pretty big range (.005-.013).
 

Dick Steinkamp

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If you find a spec, don't confuse crank shaft thrust (front to rear movement of the entire crankshaft) which is generally set when the crankshaft is installed...and con rod thrust, the side to side movement of each con rod on its crank journal.
 
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