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11-19-2017LAST POST
Hi all, pool me in with that "exclusive" group of m3 owners with rod bearing issues. The car is a 2011 with less than 50k miles and it all started with a faint quick rattle on startup when cold (around 40k miles). I called it a lifter noise at first as it went away right away and was inconsistent at best.

Just like this:

Well I was wrong. It progressively got worse (the start up rattle/knock) until it finally became a faint but consistent knock around 1000 to 2000 rpm only.

The car is waiting to be torn down to confirm but based on the obvious sound and metal debris is the oil filter it's a foregone conclusion.

What are the odds the crank isn't toast and I can just put new bearings in?

Edit: main bearings were the root cause with excessively worn rod bearings but not destroyed.
Yikes. I think we've all experienced that cold start rattle, so i'm not sure we can conclude that that sound is the RBs going bad.
shimmy23 wrote
Yikes. I think we've all experienced that cold start rattle, so i'm not sure we can conclude that that sound is the RBs going bad.
As far as I'm concerned they are one and the same, I'm convinced of it, I will post pics of the bearings as one way or another they are coming out. My issue progressed over a 4000 mile period I estimate. How long have people had the rattle for?
Duk996 wrote
As far as I'm concerned they are one and the same, I'm convinced of it, I will post pics of the bearings as one way or another they are coming out. My issue progressed over a 4000 mile period I estimate. How long have people had the rattle for?
how long? I couldn't tell/report an exact mileage but its a long time. Seems like some people have reported it as the lifetime of their ownership.

I experienced that sound after my car sat for 7 days... hasn't happened since and that was at least 5k miles ago.

Anxious to see your RBs and fingers crossed that your motor is salvageable. Hope it all works out man!
OP - Can you comment on your use and oil change interval? I'm one of the believers that RB's are a service item on these cars and have planned to do it at 60k miles.
Duk996 wrote
As far as I'm concerned they are one and the same, I'm convinced of it, I will post pics of the bearings as one way or another they are coming out. My issue progressed over a 4000 mile period I estimate. How long have people had the rattle for?
No , they are NOT the same . Your situation are actually 2 different WORLDWIDE S65 problems .

1- You had the cold start clunk noise => http://www.m3post.com/forums/showthread.php?t=996069&highlight=LIMITLESS

2- And later (from your description) you got probably bearing failure => http://www.m3post.com/forums/showthread.php?t=786615

Note : Most S65s are having the cold start clunk noise when they are NOT daily driven (garage queens)
S65 daily drivers don't have the cold start clunk noise , and garage queens from 2008 till 2013 are still running fine TODAY with the cold start clunk noise and without bearing failure .

The cause of the cold start clunk noise are the S65 Vanos-Gears and they have nothing to do with the S65 bearings or with bearing failure .
Bimmer Barney wrote
OP - Can you comment on your use and oil change interval? I'm one of the believers that RB's are a service item on these cars and have planned to do it at 60k miles.
Sure, all oil changes done by the dealer save 1; when called for by the car. No tune or tracking. I wind the thing out every once and a while but no overrevs (at least by me, as of 34000 miles).

I don't see this as being an oil change issue. From what I have researched BMW uses half the industry standard bearing clearance and it seems to be a problem. It looks like even "good" bearing have wear and that's unacceptable. There should never be metal on metal contact with a bearing. I have yet to see bearings come out of these things w/out wear...granted I haven't been searching for unworn bearings online....

I'm at a loss, I don't know what I could have done differently.
Bimmer Barney wrote
OP - Can you comment on your use and oil change interval? I'm one of the believers that RB's are a service item on these cars and have planned to do it at 60k miles.
RB's are not a service item . I saw S65 from 2013 with bearing failure in 2013 with only 6,700 miles on it .
Some owners had bearing failure twice , and run today with their third S65 .

On the other hand...The S65 bearings *BECAME* a service item by the WORLDWIDE S65 bearing failures .
///M Power-Belgium wrote
RB's are not a service item . I saw S65 from 2013 with bearing failure in 2013 with only 6,700 miles on it .
Some owners had bearing failure twice , and run today with their third S65 .

On the other hand...The S65 bearings *BECAME* a service item by the WORLDWIDE S65 bearing failures .
nicely put
SYT_Shadow wrote
nicely put
Thank you Sir ! :thumbsup:
That noise in the video is NOT related to the rod bearings. Like Belgium said, it happens when the car isn’t driven daily. Mine did that when I didn’t drive it for a few days or a week. But if it’s driven everyday it doesn’t make that noise.
Munichm3 wrote
That noise in the video is NOT related to the rod bearings. Like Belgium said, it happens when the car isn’t driven daily. Mine did that when I didn’t drive it for a few days or a week. But if it’s driven everyday it doesn’t make that noise.
I suppose, I like my hypothesis that on start up the bearing is worn and knocks until the oil pressure arrives to cushion it all. That would be consistent with the garage queen theory in that the oil between the journal and the bearing would "leak" out when left for a period time setting up to audibly knock again on next start up.

I can't explain how people would have that knock/rattle on startup and NOT have it escalate into a full blown constant knock while running though.

I'm open to whatever. At this point I just hope the journals are not damaged.

Mine makes the clunk when not driven for a day (@ 12 seconds)
WingZeroX5 wrote

Mine makes the clunk when not driven for a day (@ 12 seconds)
Yep , that's the cold start clunk noise and the same as my S65 .
Note : In your video I can hear a squeaking noise , probably it comes from your drive belt or wear from your pulley axle .
///M Power-Belgium wrote
WingZeroX5 wrote

Mine makes the clunk when not driven for a day (@ 12 seconds)
Yep , that's the cold start clunk noise and the same as my S65 .
Note : In your video I can hear a squeaking noise , probably it comes from your drive belt or wear from your pulley axle .
Yeah I heard it too. Very faint. But In that video I changed all belts too. Maybe needed a short time to break in, but I do not hear it anymore since then
WingZeroX5 wrote
///M Power-Belgium wrote
WingZeroX5 wrote

Mine makes the clunk when not driven for a day (@ 12 seconds)
Yep , that's the cold start clunk noise and the same as my S65 .
Note : In your video I can hear a squeaking noise , probably it comes from your drive belt or wear from your pulley axle .
Yeah I heard it too. Very faint. But In that video I changed all belts too. Maybe needed a short time to break in, but I do not hear it anymore since then
Is there any chance BMW will own up to making any of this right? At least in my case?
Wow, mine is sometimes not driven for a week and I don’t get that clunk.....hope I never do.
Duk996 wrote
Is there any chance BMW will own up to making any of this right? At least in my case?
Nothing is wrong with that noise on start up. Like said, people have had it for over 100K miles and it never did anything. Belgium states it’s the vanos gears which it is.
I hear a rattle once in awhile immediately upon startup, I always thought it was the timing chain tensioners, but that is from my past experience with every BMW that used a hydraulic timing chain tensioner. I purchased a pair of tensioners, but haven't installed them.

Also I had my rod bearings done recently, and the cold start rattle is exactly the same now as before I changed the RB.
Duk996 wrote
Is there any chance BMW will own up to making any of this right? At least in my case?
From your description in your # 1 post => *Metal debris in your oil filter*
Straight to the point , this sounds pretty bad . And personal I think your S65 is R.I.P .
Of course I'm not 100% sure . But your situation sounds NOT good !

I wish you the best of luck with your S65 .Please keep us posted about your situation ....
Munichm3 wrote
Nothing is wrong with that noise on start up. Like said, people have had it for over 100K miles and it never did anything. Belgium states it’s the vanos gears which it is.
One guy fixed the cold start clunk noise by replacing the S65 Vanos-Gears under BMW warranty .
Here is the paper of the S65 PUMA-case ..
Attached image
Good stuff Philippe, as usual