Found Metal in Oil Filter – What’s Ferrous Besides IMS Bearing?

[Jvarghese]

Just did an oil change after a 3,000-mile interval on my 189k-mile car, and some things caught my attention:

-The oil looked pretty dirty coming out.

-I’m running the LN Engineering spin-on filter adapter.

-After cutting open the filter, I found a few small non-ferrous (aluminum?) bits near the paper.

-More concerning: a noticeable amount of ferrous material in the pleats, which I confirmed with a magnet.

-I saved the filter oil in a bottle and already sent it out for analysis—now just waiting on the results.

Main question:
Besides the IMS bearing, what other components could be shedding ferrous material into the oil at this mileage?
At this mileage if I have to do the IMS what else should I replace while I have engine and transmission out?

Would really appreciate thoughts from anyone who's seen this kind of debris before trying to stay ahead of any major issues.

Thanks! - here are some pictures

[78F350]

"... Besides the IMS bearing, what other components could be shedding ferrous material into the oil at this mileage?..."

Timing chains and crankshaft bearings come to mind as potential sources of ferrous metal.

[Gilles]

Originally Posted by 78F350

"... Timing chains and crankshaft bearings come to mind as potential sources of ferrous metal.

With 189k miles, perhaps be a good idea to check the cam deviations, as it coild be time to replace the chains?

[Homeoboxter]

I think the superficial layer of the bearing material is not really ferrous and comes in flakes. It's more likely that one of the chain pads is worn down and disintegrated and the chain runs on metal grinding ferrous debris into the engine. I'd pull the sump and take a look at what's inside. Checking cam deviations and actual cam angle are also good ideas to confirm, as suggested by Gilles. You can also listen to bearing noise under the IMS, if it's bad, probably should be audible. But most likely the engine needs to come out if you want these fixed...

[Jvarghese]

Really appreciate all the insight—thank you! I’m planning to dive into it this weekend, starting with dropping the sump to see what’s inside.
note: the water contamination you see is from the fact I had it transferred from a water bottle because I didn't have the sample kit at the time.

In the meantime, here are the oil analysis results.

[DAB986]

Just joined the forum recently and came across your post on metal contamination. I have a '98 as well--silver with red interior.

Since it is now July, I assume you've already found the cause of the metal contamination in the oil. Hopefully, it ended up not being too big of an issue, but given the lab results, my first thought was that (in addition to one or more of the other previously mentioned issues in this thread) you might be seeing the initial stage of bore scoring, or at least wearing of the iron coating on the pistons that ultimately leads to bore scoring. At this point, it might not be bad enough to see increased smoke in the exhaust.

I believe a lot of people would be interested in your findings, and how it was resolved. Also, have you ever run a diagnostic on the car to look at the history of potential engine over-revs? Though bore scoring is a potential issue with any high mileage M96/M97 engine, it is my understanding that the early M96 engines tend to be less prone to it (as well as de-chunking) because they have a shorter stroke than the later engines and use cast aluminum pistons, which have a more robust iron coating than the forged pistons found in the later engines.

[997_986]

Originally Posted by DAB986

[...] it is my understanding that the early M96 engines tend to be less prone to it (as well as de-chunking) because they have a shorter stroke than the later engines and use cast aluminum pistons, which have a more robust iron coating than the forged pistons found in the later engines.

No, the reason these "low power" M96 engines do not suffer from scoring is due to the fact that their cylinder walls are thick enough and cooling sufficient. The concept was not bad at all. The problems began with ever larger displacements and thinner cylinder walls in combination with inadequate cooling.

Please do not start a "scoring thread" ;-)

[DAB986]

With all due respect, I am not starting another bore scoring thread--just stating the facts relevant to your initial oil analysis.

I STRONGLY suggest you watch the Porsche Club of America's 4-part Youtube video on bore scoring to get the actual facts on the causes of scoring (which do not comport with your assertion).

The videos are entitled "How to Prevent or Slow the Progression of Bore Scoring in your Porsche M96/M97 engine." I recommend you watch all four videos.

Good luck.