Main Thrust bearings

[1991 E30 M42]

There is a copper coating under a silver colored coating, so if you have copper flakes in the oil you have already worn through the outer coating. How noisy is the engine?

[KenC]

There is a copper coating under a silver colored coating, so if you have copper flakes in the oil you have already worn through the outer coating. How noisy is the engine?

Engine is currently being rebuilt.  I've never seen any copper flakes.  My rod bushings are still silver and look to be in pretty good shape.

[Nomadic]

Copper colored material is what you see after the other metal has worn away, I have seen it three times in this engine and several times with others. Did the oil look somewhat milky? I will dig around and see if I can find pictures of the metal shavings that came out of the three M42's that I blew up.

Oil was not at all milky.  Compression is good.  

Thanks for posting those photos.... scary.... I'm pulling her off the road till I can show the shavings to a local expert.  

--If I really have bearing shavings... what are the chances my crankshaft and rods are still salvageable?

--Is it possible to swap-out bearings from under the car... by pulling upper pan  w/o pulling the motor?

Thanks again.

[1991 E30 M42]

Oil was not at all milky.  Compression is good.  
--If I really have bearing shavings... what are the chances my crankshaft and rods are still salvageable?

--Is it possible to swap-out bearings from under the car... by pulling upper pan w/o pulling the motor?
Thanks again.

it really depends on alot a varibles, I have seen bearings go bad but the crank still look good, but I have also seen them ruin a crank. The last engine I tore apart, which is the engine that the bearing in the picture came out of, the crank needed to be reworked.

As far as doing it from underneath, It is possible but in the time it will take you to get the oil pan out, which in this car I think it requires the removal of the subframe, you may as well just pull the entire engine which takes me about 2 hours for the tranny and all. It isn't an extremely difficult job but there are a few things you need to remember to get it back together.