Need some advice - BMW N52 engine with non metallic flakes in oil filter

[J0shTN]

My 128i with 123k miles that I recently acquired shows 1 previous owner and regular maintenance history at the BMW service center.

I pulled the oil filter after some rough running with a CEL and noticed the filer was collapsed a bit so I installed a new Mann filter. I cut open the old filter and noticed a large amount of brown and black particles.

I did start the car and ran it for a few minutes with the new filter. No issues, CEL, or abnormal sounds/vibration. I pulled the new oil filter after that startup and noticed no similar particles.

I lowered the oil pan for a gasket replacement and looked inside the timing chain area and near the rear crank seal where I found a layer on the interior wall is peeling off. What are your thoughts on the layer of material? Oil varnish related?

What would you do? Part of me is saying remove what I can access with the oil pan and valve cover removed and then trust the oil filter to do its job. Then inspect the oil filter religiously for a while. Aside from a full teardown, are there known tricks to remove this or am I better off leaving things as-is?

 

[dbias]

Plastic chain guides?

 

[J0shTN]

Best I can tell it’s the same material as the layer photographed on the wall inside the engine. Couple of photos show where the layer of material has flaked off. There were no large guide pieces in the oil pan. All of the solids are flat shaped, same thickness, and very brittle.

 

[meep]

Car was regularly maintained but the filter sounds like it was loaded up… I’d start changing the oil sooner. i might consider an oil flush or running it with half a can of sea foam in it for a thousand miles and doing an oil change, maybe wash rinse repeat. after doing that some, check the pump pickup screen. I don’t think this is serious but I’d want to keep an eye on it and see if it could be “helped“ along.

also stick with a good synthetic oil if you aren’t already.

 

[DemoFly]

I have never seen anything like that before.

 

[Rand]

That looks bizarre, mini pieces of shale.

Whatever I did I would change the oil and filter more often you dont want those bypassing around the engine.

 

[BMWTurboDzl]

What does it feel like? Can you break it down between your fingers or is it hard?

I looks like some oil additive.

 

[J0shTN]

Thanks everyone. The loose pieces are easily broken into smaller pieces. BMW recommends a pretty long OCI, so I can’t help but think this is a byproduct of that and possibly using a non approved oil. Another thought that was shared was maybe it is remnants of an oil leak stop fluid.

An initial engine oil flush and oil change after no load running and then waiting a few hundred miles to use sea foam prior to an oil change seems like a good idea at this time.

 

[jeepman3071]

Thanks everyone. The loose pieces are easily broken into smaller pieces. BMW recommends a pretty long OCI, so I can’t help but think this is a byproduct of that and possibly using a non approved oil. Another thought that was shared was maybe it is remnants of an oil leak stop fluid.

An initial engine oil flush and oil change after no load running and then waiting a few hundred miles to use sea foam prior to an oil change seems like a good idea at this time.

That was my first thought, some form of additive/oil stop leak. I would be doing short OCI's or at least filter change intervals to get it all out. I wouldn't do any oil flushes or harsh cleaners like seafoam, that sounds like a good way to dislodge everything at once and clog something important like the oil pickup. Congrats on the 128i those are really fun cars.