Small gold flecks in oil but not rod bearings? (**Update Main Bearing pics included)

[miles3719]

Hey all,

Sorry for YAFRBP (Yet Another F... Rod Bearing Post )
I am about to go through the fun and games of bearing replacements with my mechanic doing an engine out main+rod bearing job becaue of finding this during a routine oil change (1500 kms after I bought the car w/92,000kms... so FUN and games right there hey)

Getting pictures but after pulling the rod bearing out (ACL Race bearings) we found they were 'worn but not coming apart and not spun. So then it was suggested to move onto the mains and check those. So with the main bearings out (King Race bearings - need to try and determine p/n of them) we found that the main bearings showed somewhat uneven wear on the closest side to the chain. Appreciate that without pictures that is nigh on useless information but i will get more when the pics come.

So we sat down and since the engine is out on a stand decided to replace the rod bearings with BE Bearings + BE spec bolts w/ King pMax blackrace bearing (MB5803XP STDX), basically the same combo that M539 used and measure everything to see if its in spec since BMW have different main spec bearing colours and aftermarket tend to just have a standard 'set' size and you pick.. STDX in my case.

So getting to the point (finally), if the glitter in the oil does not appear to be a self destructing bearing, what else could it be? The kicker here is that its been communicated to me that about 3 owners ago (and 25,000kms) ago, the bearings were replaced which leads me to beleive that is true given they're obviously not OEM so at some point they were done and i dont have a reason to suspect the claim of them being one at 75,000kms or so was incorrect. The car has had 3-4 (I am told) oil changes since the bearings were done, so any leftover debris from the previous bearing(s) should have been well and truly cleaned out by now? These flecks would notionally have to come from between the last service and now yes?

Just fishing for thoughts and insights. Does not look like the normal glitter that others see with bearings as in its not 'chunky' like other pics I have seen but flat and golden that you cannot feel through your fingers I am told

[CamasM3e93]

Originally Posted by miles3719

Hey all,

Sorry for YAFRBP (Yet Another F... Rod Bearing Post )
I am about to go through the fun and games of bearing replacements with my mechanic doing an engine out main+rod bearing job becaue of finding this during a routine oil change (1500 kms after I bought the car w/92,000kms... so FUN and games right there hey)

Getting pictures but after pulling the rod bearing out (ACL Race bearings) we found they were 'worn but not coming apart and not spun. So then it was suggested to move onto the mains and check those. So with the main bearings out (King Race bearings - need to try and determine p/n of them) we found that the main bearings showed somewhat uneven wear on the closest side to the chain. Appreciate that without pictures that is nigh on useless information but i will get more when the pics come.

So we sat down and since the engine is out on a stand decided to replace the rod bearings with BE Bearings + BE spec bolts w/ King pMax blackrace bearing (MB5803XP STDX), basically the same combo that M539 used and measure everything to see if its in spec since BMW have different main spec bearing colours and aftermarket tend to just have a standard 'set' size and you pick.. STDX in my case.

So getting to the point (finally), if the glitter in the oil does not appear to be a self destructing bearing, what else could it be? The kicker here is that its been communicated to me that about 3 owners ago (and 25,000kms) ago, the bearings were replaced which leads me to beleive that is true given they're obviously not OEM so at some point they were done and i dont [...]

Thinking of it in terms of color, what’s in the engine that is gold or brass….

Leftover foreign debris from the prior bearing job

Does your oil pan have a timesert thread insert installed? It’s brass colored

Vanos device, timing chain and sprocket - you would have seen these during the main bearing job

There’s not much else that is that color. Let us know what you figure out

[miles3719]

Thanks will do CamasM3e93 , vanos cover is off now anyway as needed to take crank out anyway and im then going to be installing SLON vanos covers that I bought.

Don't think so on the timesert but ill get it checked and as you say the crank sprocket etc we might have seen. Are investigating further but as soon as we was those flecks we jumped straight to rod bearings, then to main bearings (where the expensive fun of removing whole engine began) to sort of come up empty.

Leftover debris is my thought too, but how many oil changes would it take to remove it?

My thinking along those lines would have beeen

1) Engine blows / something happens
2) Owner gets 2nd hand engine and says to shop (reputable one here in AU for S65), "sell me a 2nd hand engine and do the rod and main bearings please "... which were done looking at the fact they're not OEM
3) Shop installs engine and leaves all ancillaries as they were (possibly contaminated with bearing debis as you say)
4) Car goes on to have 3-4 oil changes since bearings done.


So with my thinking (am I missing anything?), would the oil changes since the engine change have cleaned out what was floating around from the assumed broken engine?

Obviously I am going to have the oil cooler, lines and block cleaned and flushed as much as possible. hopefully this diagnostic work will present something that can be fixed.

[miles3719]

Attached are the pictures of the main bearings that have come out of the engine. They are purported to have travelled approximately 25,000 kms (15,000 miles)

Seems like a lot of scraping to my untrained eye. I post these to get the groups expert opinion.

Also they are Kings pMAX std bearings. It was suggested to purchase STDX replacements, so I have done this and that is what will (with current/present logic) be the ones going back in. With standard/stock internals, is this something that is common?

FWIW the oil being used will be Liqui Moli Racetek 10w60 w/Ceratec.

I would love some observations/suggestions/thoughts if possible please?

TIA!

[RocketyMan]

Can you post the upper bearings? More specifically the upper main #1?

[deansbimmer]

I don't see any indication of failure, but have some thoughts.

-The brown/amber color of used engine oil will cause any metal content in the oil to appear as copper. If you were able to separate and rinse the metal debris in, say, a paper coffee filter, you'll probably find they're actually silver. If you do this and they are indeed bronze or copper then you might have a problem.

-There appears to be an excessive amount of debris embedment in the bearings and evidence that a lot of material went through those bearings causing light scoring. This is common for a lot of bearing replacements that were not done in a super-clean environment. It's why we state that mains must be done as a complete teardown in a clean environment. Otherwise there's just too much carbon, dirt, etc to manage, and it'll end up circulating through the engine and result in that kind of wear.

-Always replace the oil cooler after any kind of bearing failure or suspicion of such. You will never, ever, be able to remove all of the debris from a cooler. You just can't- no matter how much flushing you do. It sucks but you just gotta do it if you want a proper long term outcome. You can flush the hoses- those are ok to reuse.

[swalko]

Do you have some update?

[charliev68]

Reminds me of the Toyota engines that are suffering from machining debris left in the block killing all their brand new engines.

[GORDON.M3]

Those mains actually don't look too bad at all.