[2007e90335i]

Hi everyone,

Note about condition of car beforehand: Around 2 months ago I was told by the bmw dealership that my car had been leaking oil but they didn't know where it was coming from. But it was dripping below the oil pan area underneath my car. I've just been filling up my oil levels every now and then but now have ran into another problem and should probably get it checked out...

I need help with possible diagnosis on my 2007 e90 335i. Yesterday after work, about 8 hours before last drive to work, started making a grinding... sort of rattling sound. The noise you would imagine if your brake pads were low but probably not the brake pads.

I checked the engine bay and noticed some oil and dried bits around the oil filter housing. After driving for 10 minutes, the noise was gone when I checked while driving slowly.

What may be the problem? Any help or advice appreciated!
Here's a picture:

[marvinstockman]

The picture you show is oil weeping, and is probably not your problem.

Do you check you oil between oil changes. If so, how much is car using/burning/weeping/leaking.

If you clean your engine compartment, you can then add special UV dye to the oil, and after a few days of driving, search for the leak with a UV light.

[E92William]

First off you're leaking pretty badly from your oil filter cap. This has an o ring thats supposed to be changed every oil change which I'm sure if you dont do your own, hasnt been changed. This oil can get on your belt and cause it to slip and wrap around your crank pulley then get pushed into your oil pan through the crank seal, get that addressed. Also check if the oil filter cap has the cage that holds the filter inside, if missing this can leak oil pressure down into the drain that the cage covers, into your oil pan.
Regarding the rattling noise, given that that is a 335i n54 its 99% the wastegates just making noise. With the engine cold, reach down on the exhaust side of the engine and you'll see a metal rod by where the turbos are, if that has play you likely have wastegate rattle.

[ctuna]

I agree oil filter cap and o ring most likely
somebody did not change that filter correctly .

And you want to be hypervigilant about oil leaks
at the front of the engine or you get this
broken belt
https://www.e90post.com/forums/showthread.php?t=1305990
http://www.bimmerfest.com/forums/sho....php?t=1231881
http://www.e90post.com/forums/showpo...3&postcount=23
http://www.e90post.com/forums/showthread.php?t=1477111
https://www.oxwerkzperformance.com/

[mainbearing]

Yes, I would think the large cap o-ring, as it certainly does not look like any leak from the filter housing gasket below is going to work its way up like that.

I would also be concerned if the cap's center gage is still there, as I read that oil pressure would drop and there will be wear on the components.

[Wolf 335]

Your tensioner pulley also looks like it has lots of oil curd built up on it.

And not to mention the score/gouge line in your belt.

You need to address that before it slips or breaks, because then $300 job turns into a $800 job

[nsjames]

Originally Posted by Wolf 335

Your tensioner pulley also looks like it has lots of oil curd built up on it.

And not to mention the score/gouge line in your belt.

You need to address that before it slips or breaks, because then $300 job turns into a $800 job

this

a contitech belt kit is less than $100 and may save a motor.

you need to clean up all that mess, but o ring for sure, which also makes me wonder if the plastic cage is installed correctly inside.

Do you have any smoking at stop ights or such under the hood? bad burnt oil smell in the cabin?
that's valve cover.
valve cover.
the oil filter housing
the oil pan

are the most common leaks.
valve cover and OFHG are ones to worry about, oil pan gasket isn't worth the hassle unless it's major.
Mine leaks, yet I went nearly 10K miles this last oil change and still didn't have to add oil.