More rod bearings

[CSBM5]

Originally Posted by leisey

Even though my oil analysis was good and no rattles. I had the bearings changed. I have owned the car since 24,000 miles. So I added a 103,000 miles with 2 track weekends.While there is some normal discoloration on the upper bearings, just like 2 M30 motors I have pulled apart, the bearing are fine. I measured them with calipers and can find no measurable wear. Which means it is in the tenths of .001". After all the horror stories and my plans to keep it, I needed piece of mind. I have personally instructed one student at a HPDE event in a E92 and his locked up. He had just bought the car used with about 50K on it. Go figure.

Thanks for the post. For 127,000 miles, they look very good. I assume you went with BE bearings?

[Duk996]

Originally Posted by admranger

What's the mechanism for the cracks in the block? Just heat?

Is there any value in getting a higher mileage used motor than a low mile unit? From the few older M20, S50, and M52 motors I've torn down, the cross hatching was still there in the bores. Perhaps just re-ring the higher mileage motor is a better value than buying a low mile unit?

Hopefully I never have to face this issue, especially now that I'm out of my Vegas house that had the lift in it and had room to pull engines, etc.

Sorry to those affected by this situation. I replaced the RB's on mine and 2 other S65's last year with bebearings. Not a lot of fun to do the work, but way more straightforward than replacing the mains.

Im guessing heat is the main contributor followed by whatever high pressure spots because the bearing isn't loaded uniformly anymore. The bouncing around my crank seems to have done didn't help either...Finally the oiling hole is stress a concentrator. Mine cracked right down the webs along the oiling holes.

I don't think throwing whatever pistons with new rings into a used but still cross hatched bore is going to cut it. I'm not going to do it. My cheapest way out is to get a low mileage top end and rebearing the bottom end. I'm still weeks out though and still jingling options.

[deansbimmer]

Yes, the cracking is from thermal expansion and contraction. The web is thinnest there due to the oil hole and therefore subject to faster heating. Without maintaining a consistent temperature in relation to the surrounding material, the aluminum eventually cracks. These S65 mains crack in the exact same spot.

These Alusil blocks don't have cross hatching like iron blocks do. To re-ring there is a bit of debate as to what works and what doesn't and is beyond the scope of this thread. Some classic Porsche owners have re-ringed a used bore with no prep other than cleaning with solvent. I believe someone reported back that after a few thousand miles they started to see smoke from the tailpipe so it's not safe to assume that this method is a long term solution. It goes against the proper procedure.

The correct way to re-ring is to hone the bore with a felt hone and Alusil honing compound until the proper surface is achieved. This is not a cross hatch or a stone hone. It can be done with hand tools. I did it on an M62 several years back and its still running great 30k miles later. The rings are expensive for S65 however, and if the bore becomes tapered or oval the you have to correct that at a machine shop. That risk becomes greater as miles get higher. Google Alusil honing and AN-30 if you want to read more. Not much from the BMW scene but the Porsche guys experimented with the backyard approach.

[oldmanstyle]

Originally Posted by ///M Power-Belgium

If the car and the S65 is out of warranty it's no longer the problem from BMW . And it is no longer recognized/accepted as a problem for BMW ,because like it is described the BMW warranty is expired !

Seen from BMW's side , we/you/I and our S65/85 are history

Case closed .

The E46 RACP lawsuit was successful and it all happened out of warranty.

[Duk996]

Originally Posted by oldmanstyle

The E46 RACP lawsuit was successful and it all happened out of warranty.

Looking at the whole thing through the simple lens of right and wrong it seems BMW should be held to account in some way. Something is going on with these bearings.

I recognize people and the legal system are imperfect though.

[BOOF-M3]

Originally Posted by Duk996

Looking at the whole thing through the simple lens of right and wrong it seems BMW should be held to account in some way. Something is going on with these bearings.

I recognize people and the legal system are imperfect though.

It's going to happen. Especially if they start dropping like flies.

[///M Power-Belgium]

Originally Posted by BOOF-M3

It's going to happen. Especially if they start dropping like flies.

I agree . Even the list on Bimmerpost became long..Knowing that the list on Bimmerpost is only a small part of the worldwide bearing failures ..

It's going to happen ?
There is only a very small chance this will happen .
And if it happens...What can BMW do about it ?
BMW had/has no fix ..

[///M Power-Belgium]

Originally Posted by pbonsalb

I think that is more than normal discoloration.

Originally Posted by Duk996

Agreed, I don't think your supposed to wear through the various layers...still, hardly bad by m3 standards.

Exactly .

[CSBM5]

Originally Posted by ///M Power-Belgium

I agree . Even the list on Bimmerpost became long..Knowing that the list on Bimmerpost is only a small part of the worldwide bearing failures ..

It's going to happen ?
There is only a very small chance this will happen .
And if it happens...What can BMW do about it ?
BMW had/has no fix ..

At best it would be something like everyone getting a voucher for $500 off a new BMW while the law firm will take away millions -- "justice will have been served."

[pbonsalb]

Or maybe BMW would extend the engine mechanical warranty to 10 years. That would not help me much with my 08. I did the rod bearings and am now considering main bearings. It’s still easier than rebuilding a motor but enough of the same labor is involved that I would consider boring it if I have the money at the time, but I suppose that extra money could alternatively go to a supercharger.

[admranger]

Originally Posted by Duk996

Im guessing heat is the main contributor followed by whatever high pressure spots because the bearing isn't loaded uniformly anymore. The bouncing around my crank seems to have done didn't help either...Finally the oiling hole is stress a concentrator. Mine cracked right down the webs along the oiling holes.

I don't think throwing whatever pistons with new rings into a used but still cross hatched bore is going to cut it. I'm not going to do it. My cheapest way out is to get a low mileage top end and rebearing the bottom end. I'm still weeks out though and still jingling options.

Best of luck to you. It's unfortunate you are in this position...

[GORDON.M3]

Originally Posted by Duk996

Im guessing heat is the main contributor followed by whatever high pressure spots because the bearing isn't loaded uniformly anymore. The bouncing around my crank seems to have done didn't help either...Finally the oiling hole is stress a concentrator. Mine cracked right down the webs along the oiling holes.

I don't think throwing whatever pistons with new rings into a used but still cross hatched bore is going to cut it. I'm not going to do it. My cheapest way out is to get a low mileage top end and rebearing the bottom end. I'm still weeks out though and still jingling options.

Could you visually see your crank bouncing? Is it something you could open the hood and notice?

[Duk996]

Originally Posted by gordon@

Could you visually see your crank bouncing? Is it something you could open the hood and notice?

Are you being sarcastic? I didn't even know the knocking was the crank until I had it all apart; I figured it was a rod knock.

No oil leaking around front or rear main seals, certainly couldn't see it with the hood open. You can't even see the crank with all the accessories in the way. We are talking thousandths displacement...