View Single Post
      03-25-2014, 02:18 PM   #260
regular guy
Lieutenant Colonel
427
Rep
1,947
Posts

Drives: Sprint car
Join Date: May 2013
Location: California

iTrader: (0)

Quote:
Originally Posted by tom @ eas View Post
In the middle of a rod bearing replacement on a supercharged-prep M3 and noticed something odd on #3 rod bearing (upper):

Info
Vehicle: 2008 BMW M3, DCT
Production Date: 07/08
Oil Used: TWS Motorsport 10W-60, no data provided on previous oil change
Mileage: ~30,XXX mi
Fuel: 91 Oct
Driving Habits: Mostly highway/street driving, no track use

This is plastic wrapping that was left on the bearing during engine assembly, which was enough to provide pressure on the bearing and causing excessive wear on the upper bearing cap as evidenced below.









More info shortly as we look into this further.
Notice how it created a heat-generated discoloration of the bearing. I've seen a few sets of bearings also with heat-generated hot spots on them. Any idea how thick that piece of plastic is? Any way to get a micrometer on it?
Appreciate 0