I own a 2013 E63 with 145,000 miles. Over the past 40,000 miles, the engine has developed two major oil leaks from the Oil Filter Assembly. There is a 1.5 inch black plastic 'oil filter cover' (PN A278 180 04) that is located in front of an internal valve and a spring within the Oil Filter Assembly (#50, 60 & 70 in the MB diagram). For some unknown reason, this assembly pushes on the black plastic 'oil filter cover' which then spews engine oil. WHAT IS CAUSING THIS TO HAPPEN? The PVC / Crankcase Ventilation Filter has never been replaced, so I suspect that it is clogged, which creates too much pressure in the crankcase, which then unloads this oil filter valve? FYI. I grabbed some of these Oil Filter Assembly photos from a You Tube video regarding the same subject but there was no explanation for the issue so I'm seeking help. I am grateful for your knowledge and assistance.

If this was my 12 year old high mileage high performance German car with known fragile plastic underhood parts that crumble with age, I would throw parts at it.

Start with the immediate issue(s) at hand and simply replace everything in your line of sight and follow the yellow brick road until the problems are gone. You will ultimately end up replacing everything plastic underhood.

You 140k.Mi. M157 is leaking oil from multiple places...You already understand this comes from crankcase pressure.

> How to deal with that ??

• you can reduce crankcase pressure...
• replace PCV + plugged up duscharge hose Line
• decrease pistons blowby pressure leak
• replace only few hardened oil seals
• fix known leaks (CPS) & issues (stuck rings)

filter CAP + cooler + Tstat
Nos 170 +180
Nos 60 + 50
No 90 (+ O-rings)

The more you seal crankcase pressure by replacing new seals, the more it's going to stress your rear main seal and timing cover seals too. Either may become a terminal condition.

So reducing the source of blow-by pressure should be a top priority, not the dirty leaks.

Thank you for that information. I too suspect that crankcase pressure is the dominate cause. I will post the results here on this thread.

... clear focus will get you better, safer, cheaper results.

High blow-by leaks evolves with colaterals:

1. misfire faults
2. engine vivrations
3. reduced output
4. spongy throttle
5. poor shifts
6. extreme heat
7. oil consumption
8. carbon'ed valves
9. Contaminated Lambda
10. VacPmp check-valve
11. CPS: "$10k-oil-in-harness!"
12. .....

Stick with the root-cause else repairs too expensive!