I've pulled the engine on my '09 Cooper S to address some oil leaks and replace the timing chain and clutch. There were obvious leaks from the front seal, valve cover, and perhaps the oil pan and oil cooler. What has surprised me is how full of oil the bell housing is. The clutch and flywheel are dry, but the starter and bell housing are saturated with oil. I'll replace the rear main seal, but I'm wondering about the two 12mm Allen head caps, are they a source for oil as well? Also, with the number and severity of the leaks I'm wondering if my engine is being pressurized by a blocked PCV.

 

Rear main seal usually is all the leaks.

https://www.northamericanmotoring.co...an-gasket.html

https://www.realoem.com/bmw/enUS/sho...diagId=11_3908

I see its number 11 and 12 and not many people have replaced them. I dont see many people talking about those two allen bolts.

 

PVC is built into the valve cover usually replaced.
the oil filter housing usually turbo lines leak oil.

 

Those Allen caps should be tight, be sure to check and see if they are. I thought my rear main seal was leaking after replacing it while doing the clutch....only to find out those Allen caps were finger loose and pissing oil out once started.

Id replace the RMS, tighten those Caps, replace all the gaskets you can and then go from there.

 

Thank you for the input, I'll snug the Allen caps once I get the engine off the stand.

So far the only oil seal that isn't leaking is the head to HPFP interface. It's been discouraging.

 

We had to replace the allen bolts when we did the clutch - they were leaking. They come from Mini with a metal gasket/washer. There's also one facing upwards at the back of the engine block (under the air intake).