Rod Bearings at 50K miles

[B737Capt]

Greetings just wanted to pass a long a few pictures of my S85 rod bearings. I'm the second owner of a 2008 M5 and the car is totally stock. We have had a few here in the states lose their motors for spun rod bearings, so at 50k miles I decided to take a look. I changed them out myself. Not good. The scared shells are the upper.

Edited by B737Capt on Friday 26th July 17:45

[B737Capt]

SMG, I'm the second owner, no track time and yes 10w60. Big discussion going on now is that the oil is too heavy for cold start ups and if used as a daily driver, go to thinner oil. I bought from the dealer that sold the car new and have all records. It is stock, original rotors, more than 50% of original brake pads left, has original clutch still in it with no slip. IOW this car has not been beat on. Many with the M3 S65 motor with same exact connecting rod and rod bearings have switched to M1 0w40 oil and change at 5k. As these motors are getting a few miles on them now, spun bearings are starting to show up.

[B737Capt]

That is the exact advice being given over here now that this is popping it's ugly head up. Most of us don't track the car and or keep it in the upper rpm band where the TWS really shines. I think for normal around town driving the M1 0W40 is being floated around over here and many M3 guys have been using it with the S65. These motors were designed a while back and oil technology has come a long ways. Many think this is cold engine start up damage without letting the oil warm up.

Great points, thanks.

[B737Capt]

No I just did it early because some are spinning bearings north of 80K. That's miles. I had UOA done twice over the last 10K and the lead was very low at 8 parts and the averages are 13. No sign what so ever. I think if you hear the knock, it's too late. What we try to prevent is the crank getting damaged. That's why I'm posting this as it sneaks up on you if you're not careful.

[B737Capt]

http://www.m3post.com/forums/showthread.php?t=8564...

Here is a great thread going on right now on another forum. Some very knowledgeable engine people there. Takes a while to read but great info. My bearings are in the discussion too. S85 and S65 have same rods and rod bearings.

[B737Capt]

Yes I did them myself. I researched a while before I got enough nerve. You need a lift that allows the front suspension to hang free. You need to support the motor from the top by the 2 hooks. I bought 2 engine support bars that go across the motor and the inner fender supports the bars. The front suspension has to be lowered to get the pan out. Finally after you get the pan off, the bearing change is easy. You do have to remove the vanos pump and engine oil pump. Very easy. I went a head and replaced that high pressure vanos hose inside the block while I was there as they have been known to leak. Didn't want to go through all that again later so I refreshed it with a new one while I was looking at it.

Edited by B737Capt on Friday 26th July 17:49

[B737Capt]

My thoughts exactly when I saw that a few days ago.