N52 - Particles in oil filter

J0shTN · 10-24-2023, 08:14 PM

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

I drove it over the weekend and the car started making a whine and would stall at stops with a CEL. On restart the CEL would clear. I was able to drive it home and pulled the oil filter. There I 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 am thinking this is guide material since I see brown. The pieces are easily broken and not magnetic.

What else could it be? I didn’t think guides were a problem on the n52 but plastic isn’t going to last forever. Edit-after looking closer at this the particles are all flat and very brittle, making me think this is a coating that has deteriorated, maybe off the inside of the carbon steel oil pan?

I was soon to start the oil pan gasket replacement. The contents of the oil pan may tell the full story. What other scope items would you add to further investigate this?

AmuroRay · 10-26-2023, 12:14 PM

Oh boy - it does look like part of the tensioner. You'll want to open the valve cover at a minimum, and the oil pan to be extra sure.

cerealwars · 10-26-2023, 01:11 PM

That's a bit scary. Definitely pull the stored codes. If it is the tensioner, your code will likely reflect some relation to camshaft timing.

J0shTN · 10-26-2023, 01:19 PM

Thanks, will do and I am going to run a scope in first to check for anything obvious.

I did find a similar thread on another forum. Talks of a coating inside the chamber of the timing chain. Do all of the n52s have a coating here? I haven’t found a good photo of this area yet.

https://www.bimmerfest.com/threads/b...reply_top_post

J0shTN · 11-08-2023, 06:43 PM

I lowered the oil pan and looked inside the timing chain area where I found the interior wall coating is peeling off. Has anybody else on these forums seen this?

What’s the purpose of the coating on an oil soaked block? How many parts are coated?

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.

AmuroRay · 12-13-2023, 08:34 AM

What did you end up doing?

J0shTN · 12-17-2023, 06:05 PM

I cleaned out the oil pan and buttoned everything back up with a new gasket and bolts. Removal of the layer, what I think is oil varnish, would take a full disassembly. It seemed to be adhered well, so most is probably not going anywhere. I’m going to check/change the oil filter regularly until things clear up.

10-24-2023, 08:14 PM	#1
J0shTN New Member 6 Rep 27 Posts Drives: BMW 128i 6MT Join Date: Sep 2022 Location: TN iTrader: (0)	N52 - Particles in oil filter - timing chain guides? My 128i with 123k miles that I recently acquired shows, 1 previous owner and regular maintenance history at the BMW service center. I drove it over the weekend and the car started making a whine and would stall at stops with a CEL. On restart the CEL would clear. I was able to drive it home and pulled the oil filter. There I 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 am thinking this is guide material since I see brown. The pieces are easily broken and not magnetic. What else could it be? I didn’t think guides were a problem on the n52 but plastic isn’t going to last forever. Edit-after looking closer at this the particles are all flat and very brittle, making me think this is a coating that has deteriorated, maybe off the inside of the carbon steel oil pan? I was soon to start the oil pan gasket replacement. The contents of the oil pan may tell the full story. What other scope items would you add to further investigate this? Attached Images Last edited by J0shTN; 10-25-2023 at 07:25 PM..
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10-26-2023, 12:14 PM	#2
AmuroRay Brigadier General 2283 Rep 4,146 Posts Drives: M235i Join Date: Aug 2019 Location: Florida iTrader: (0)	Oh boy - it does look like part of the tensioner. You'll want to open the valve cover at a minimum, and the oil pan to be extra sure. __________________ Mods: Yes.
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10-26-2023, 01:11 PM	#3
cerealwars Riffraff 78 Rep 86 Posts Drives: 128i 6M, 1UZ S13, '62 C10 Join Date: Apr 2023 Location: Detroit Metro Outskirts iTrader: (0) Garage List 2010 BMW 128i [0.00]	That's a bit scary. Definitely pull the stored codes. If it is the tensioner, your code will likely reflect some relation to camshaft timing.
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10-26-2023, 01:19 PM	#4
J0shTN New Member 6 Rep 27 Posts Drives: BMW 128i 6MT Join Date: Sep 2022 Location: TN iTrader: (0)	Thanks, will do and I am going to run a scope in first to check for anything obvious. I did find a similar thread on another forum. Talks of a coating inside the chamber of the timing chain. Do all of the n52s have a coating here? I haven’t found a good photo of this area yet. https://www.bimmerfest.com/threads/b...reply_top_post
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11-08-2023, 06:43 PM	#5
J0shTN New Member 6 Rep 27 Posts Drives: BMW 128i 6MT Join Date: Sep 2022 Location: TN iTrader: (0)	I lowered the oil pan and looked inside the timing chain area where I found the interior wall coating is peeling off. Has anybody else on these forums seen this? What’s the purpose of the coating on an oil soaked block? How many parts are coated? 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. Attached Images
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12-13-2023, 08:34 AM	#6
AmuroRay Brigadier General 2283 Rep 4,146 Posts Drives: M235i Join Date: Aug 2019 Location: Florida iTrader: (0)	What did you end up doing? __________________ Mods: Yes.
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12-17-2023, 06:05 PM	#7
J0shTN New Member 6 Rep 27 Posts Drives: BMW 128i 6MT Join Date: Sep 2022 Location: TN iTrader: (0)	I cleaned out the oil pan and buttoned everything back up with a new gasket and bolts. Removal of the layer, what I think is oil varnish, would take a full disassembly. It seemed to be adhered well, so most is probably not going anywhere. I’m going to check/change the oil filter regularly until things clear up.
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