Ugly Photo! head gasket protruding under oil filter housing. Horrid! oil leak, n51

[Hyperthrive]

I had posted this over at the 128 forum but someone suggested sending it over to here for more traffic since it's the same engine.

2011 128 cute and perky convertible. 135,000 miles. Bought it used from a guy who offloads trade ins for a good deal last year. I have a 2007 328i with the same exact engine, 6 speed auto, so it seemed like a good match for my wife. Convertibles are fun! Happy wife, happy life.

But..it starting dripping oil. Now its about a quart of oil per 1000 miles, getting worse.

I already replaced the oil filter housing gasket myself. Verified the valve cover gasket isn't leaking oil. The oil is making a mess everywhere.

While I had the oil filter housing off, I see another gasket below it, protruding. It didn't look right, so I snapped a picture before I put the OFH back together. I figured it somehow wasn't causing problems, so..best to leave it. But now I am glad I have the photo.

Ready? This might be disturbing to some people..

full rez
https://drive.google.com/file/d/1ore...ew?usp=sharing


IMG_3033 small 2.jpg

I'm cleaning the engine and brushing on white flour around suspect parts, and looking at the results later that night. Nothing leaks at idle in my garage. It's not the valve cover gasket. It's not the oil filter cap o ring. It's not the oil filter housing gasket. But after a drive, it leaks oil. I have more pictures of the gasket from the rear looking forward, after the housing was put back together, before and after the white flour reveal, around that gasket.

So my current theory is that the oil channel directly under the oil filter housing is a lower pressure filtered oil returning to the engine, and at higher rpms more oil is dumping through that channel. It spills out past that protruding gasket, and along and blown up the engine block up to under the intakes.

And my hope is that in NJ under 150,000 miles this will be totally covered under SULEV.

Am I delusional? How to best frame it to a dealer rep?

[jclausen]

The bolt head at the back of the picture broke off and some times they don't leak and some times they do and leak a lot. The bolts are aluminum easy to break, replace the one bolt, of course pullback the intake manifold first the runner is in the way

[Hyperthrive]

That is genius. You guys are great. That's probably it. Thank you jclausen.

I always thought the dirty oil pooling in that shallow was from oil blowing around in that area.

[Critter7r]

That gasket looks like it's squeezing out from under the alternator bracket. But I thought only V8s had alternator brackets that had coolant and oil running thru them.

[jclausen]

Unless the head had been off I would still go after the broken bolt first

[mandd]

Has jclausen has said it is 100% the bolt that is missing it's head.

Mark.

[Hyperthrive]

My BMW mechanic replaced the bolt, cleaned her up and oil leak is solved. We left that gasket as is, strange as it is. Happy to report not a drop after 3 months of use. Thanks again everyone and I'd thought to give feedback to the next person who might miss that bolt head. I couldn't trace the leak to that bore since it happened only at high revs or oil pressure, and what was left of the bolt looked intentional.