Silver sludge on drain plug?

[Luke_M]

Every time I change the oil I get this silver sludge on the magnetic drain plug. It's very soft, doesn't feel gritty but it's still concerning especially given that it's a euro s50 that was raced. Rod bearings are a big concern.

It's always had redline oil and is daily driven now but i still have gotten the silver looking sludge for 4-5 consecutive oil changes since I've owned it. I'm gonna do a UOA next oil change fwiw.

Anyone experience this or have any ideas?

[mpowerful]

Sounds like bearing lead. Id have oil analysis done asap.

[The Dark Side of Will]

It's a good idea to do an oil analysis at EVERY oil change so that you establish a history for your engine... Yes, you should do analysis ASAP. Don't wait for your next oil change.

[M3PO]

Sounds like bearing lead. Id have oil analysis done asap.

Lead is not magnetic lol

The most common sources of iron in used oil are cylinder walls, piston rings, and cams.

[Luke_M]

Lead is not magnetic lol

The most common sources of iron in used oil are cylinder walls, piston rings, and cams.

I was thinking that as well. The only part of a bearing that is magnetic, as far as I know, is the steel backing. I could be wrong however. I'm not certain of all the layers bmw uses.

Either way, not exciting.

[M3PO]

I was thinking that as well. The only part of a bearing that is magnetic, as far as I know, is the steel backing. I could be wrong however. I'm not certain of all the layers bmw uses.

Either way, not exciting.

You are correct, you would have had to wear through to the steel backing. Old rod bearing used to be copper and lead, newer bearing since 2010 can't have lead in them per EU laws so they are now tin and aluminum I believe.