Good idea!

 

I guess so. the engine oil level goes down very slowly, maybe because I don't drive too much...(I drive only 70 miles a week) If I drove more, it would be easier to assure that is engine oil. To replace a gasket, do I need to empty all the oil-contained part?

 

I'd clean everything up first like pcy said then determine where the leak is coming from exactly.
I'd doubt you'd have to drain the oil pan but you'll probably lose a quart when you take that gasket off.
You might as well do an full oil and filter change if you are due soon.

 

One thing is ensured, part-9 (http://www.realoem.com/bmw/showparts...71&hg=11&fg=30) is leaking.
I put paper tissue in the space outside the joint, only the tip of the tissue got dirty.

 

The oil is from oil fiter gasket housing and the pic of bottom of car appears to be active steering if you have that....which is quite normal. AS leaks slowly. very normal.

I would do this....

Turn off engine and allow it to cool.
Spray engine degreaser like engine bright all over the top and under car.
let sit for 15-20 minutes and hose off with higher pressure. by high pressure I do not mean a car wash bro just a normal garden hose with appropriate head.
keep hosing until all grime is off.
Let dry up a bit for about 30 min or so.
Drive car around and let water burn off and watch for a few days and see where the leaks are coming from.
Cars leak....BMWs are famous for leaking so don't worry a little oil isn't going to hurt.
Good luck.


As far as this goes ... part 9 is not leaking, part 4/5 is.

 

Right, Part 4, 5 are the two gaskets.

 

I had the oil around the filter cap myself before. The o-ring that fits around the oil filter cap was crimped. That allow very slow pooling of oil around the filter cap. That could also explain the oil near there -- getting blown around by the fan.

 

I've tried to draw arrows to what you should check. And even if these "look okay", you should still change them - costs next to nothing


I've had this on my car for many years and it ended up being the oil cooler gaskets. They were something like 30 bucks from the dealer, replacing them takes two bolts and some TLC - search the forums, there are DIYs out there

 

Finally got a vision on the leak! So it IS the gaskets! In the early freezing morning, when I start the engine, oil came right from the gasket in the front of the oil filter cap.I can find the price of the gaskets, but don't know where exactly to get them. Shall I just call the stealer?

Another question risen up along with this: it is only 2k miles after last oil change, how come the oil came out is dark black?

 

I tried to find DIY instruction, nothing in here, nothing on Youtube, nothing by google.....