[E90CPhT]

Hello everyone,

So a few weeks ago I replaced the oil filter housing gasket on my E90. Used OE parts and replaced the bolts, etc. I thought that remedied the problem. However, I ran my finger along the underside of the housing today and I think some oil may be leaking out of the bottom of it. I see none coming from the side facing the air intake or the very top of the housing, but along the bottom part where there is a white-ish rubber gasket there appears to be some oil coming out, not very fast or anything, just whenever I run my finger along the seam of the housing it feels oily and has a light brown tinge. I did not torque the bolts to any sort of spec. I just tightened them as much as possible ( I nearly stripped one using a 5/16 at which point I stopped on that one. Coincidentally, this is the one closes to the area "leaking".

This raises two questions

1) Is it actually leaking?

2) Do I attempt to tighten this bolt some more using an 8mm box end or an actual E10 torx box end? I am certain the top bolt is tight enough and I think the one nearest the firewall side is tight enough, but I am just unsure how to proceed with this last bolt. I am considering taking it to the shop to see what may be wrong. Could the white gasket below it be leaking and causing this?

Any advice regarding this would be greatly appreciated. Thank you!

[Mr.Smithers]

common problem. it is probably leaking.

[OP3NAIR]

Did you thoroughly clean both surfaces before installing the new gasket? Otherwise it won’t seal up.
A lot of people (me included) skim the new gasket with RTV then install it. The manual may say not to, but we all know what happens when you don’t.

[330istocknot]

I remember when i replaced mine... Everything looked perfect, until i turned on the vehicle! OIL! OIL EVERYWHERE! SPRAYING! it looks like i didn't tighten up the back screw... Its a little hard to get to it... I would check and make sure there is no gap between engine block area and housing....

[Bimmer Pleaser]

I’d just redo the entire job with a brand new gasket. You don’t even have to remove the manifold if it’s non turbo.

[E90CPhT]

Its not like poruing out or anything, just when I run my finger along the bottom of it, there is a small amount of brownish filth. I checked the torque on the bolts last night and everything was as tight as it should be. When I did the job, I made sure everything was as clean as possible, as far as I know. I think the white gasket underneath the housing may be the problem, Im not too sure, though. If it is leaking it is a very slow leak.

[kkasson]

Are you sure it's not just old oil seeping out? I'd spray the whole area thoroughly with brake cleaner and do your best to wipe it dry. If you spilled any oil behind the housing, it may just be migrating along the edge and looking like it's leaking.

Is the valve cover leaking anywhere? They tend to leak on the exhaust side of the engine, but not always.

The white gasket under the housing is the head gasket - it's rare for it to leak there, especially on a 2009. The 2006s had some problems with one of the head bolts cracking and it would leak from there, but it's much less common after that.

[atmosphericM]

I've never done this job in particular on a BMW but as a rule of thumb, torque specs are important. Over-torquing the bolts could lead to leaks, believe it or not. Also, I recommend tightening the bolts in a "star" pattern (like when you install wheels) so that the gasket seals correctly. It doesn't take much for a slight leak to happen. GL

[BimmerNugget]

Lol, I'm reading this thread in my driveway just as I'm about to do the OFHG on my N51. Got my ratchet extension, swivel socket, and E10 socket all ready to go.

[BimmerNugget]

Update: OFHG replacement completed. I also replaced all 3 aluminum bolts, topped off coolant, bled cooling system. Left it idling in my driveway for 15 minutes while I put the tools away. Drove around for 15 minutes, no leaks whatsoever.

$15 in parts and about 1.5 hours for me. So easy a caveman can do it. Can't believe the stealership charges nearly $400 for this.

[Bimmer Pleaser]

Originally Posted by BimmerNugget

Update: OFHG replacement completed. I also replaced all 3 aluminum bolts, topped off coolant, bled cooling system. Left it idling in my driveway for 15 minutes while I put the tools away. Drove around for 15 minutes, no leaks whatsoever.

$15 in parts and about 1.5 hours for me. So easy a caveman can do it. Can't believe the stealership charges nearly $400 for this.

that's like the easiest gasket to replace (especially on non-turbos), and the most dangerous if it is leaking.

[E90CPhT]

So, update on mine anyway, sprayed liberally with brake cleaner and thoroughly cleaned the bottom of the housing. No "leaks" at all after 20 mins of idling and 1 or 2 mins of applying the accelerator, then drove for about 25 miles the next day, dry as a bone.

Now lets repair a wiper fluid tank...

[BimmerNugget]

Originally Posted by E90CPhT

So, update on mine anyway, sprayed liberally with brake cleaner and thoroughly cleaned the bottom of the housing. No "leaks" at all after 20 mins of idling and 1 or 2 mins of applying the accelerator, then drove for about 25 miles the next day, dry as a bone.

Now lets repair a wiper fluid tank...

How many miles are on your 09 car? It's probably due for it anyways, might as well do it. I have 64.5k on my 11 328i and the OFHG came out flattened and hard.

[E90CPhT]

Originally Posted by BimmerNugget

How many miles are on your 09 car? It's probably due for it anyways, might as well do it. I have 64.5k on my 11 328i and the OFHG came out flattened and hard.

I already changed it. I was just worried I didn't torque the bolts to spec or it was leaking.

[atmosphericM]

Glad to hear it was just some residual oil.

[EnintyToo]

Originally Posted by E90CPhT

I already changed it. I was just worried I didn't torque the bolts to spec or it was leaking.

Just asking because I am curious. When you did the gasket replacement, did you drain the coolant and remove the hose and completely remove the OFH from the head? Or did you just leave the OFH connected to the coolant hose and struggle against the force the rubber hose puts on the housing? The best way to do this repair is to drain the coolant and coolant hose and completely remove the housing. Doing it that way allows for proper seating of the new gasket.