I have an Oil Leak - United Bimmer Community

**gldfshkpr** · 11-21-2007, 10:08 PM

As far as I know there are 3 main places an oil leak will occur on these cars.

1. Valve Cover Gasket - Head replaced last Spring. Obviously gasket was replaced on valve cover.

2. Timing Chain Cover - Timing chain cover replaced last year. Too soon for it to be leaking?

3. Main Seal - My clutch was just replaced this Spring. I'm assuming the main seal was replaced as well. Fair assumption?

Mechanic says the bottom of car is soaked in oil (due to previous leaks in cluding power steering fluid and timing chain cover) and suggests steam cleaning and injecting dye into fresh motor oil to discover leak.

So how would you go about diagnosing the leak? I'm not inclined to get the car steam cleaned or allow the mechanic to diagnose leak if I can do it, with your help!

**defkon99** · 11-21-2007, 10:18 PM

id say steam clean in your self buy some gunk and spray the heck out of the bottom and then take it toi one of those drive up car washes and pressure wash it off. then look for yourself.

**gldfshkpr** · 11-21-2007, 10:27 PM

Quote:

Originally Posted by defkon99

id say steam clean in your self buy some gunk and spray the heck out of the bottom and then take it toi one of those drive up car washes and pressure wash it off. then look for yourself.

Good advice. Someone advised me to use gunk to clean the undercarriage and not steam clean. I hadn't thought about using the drive up car wash. Have you done this? Should I spray from bottom and top, or just bottom?

**Dudesky** · 11-22-2007, 06:20 AM

Quote:

Originally Posted by gldfshkpr

3. Main Seal - My clutch was just replaced this Spring. I'm assuming the main seal was replaced as well. Fair assumption?

No. To replace the rear main seal, the flywheel must be removed. Many clutch jobs do not touch the flywheel unless it's necessary. The main seal is not part of a clutch job, so I'm sure they would have told you if they replaced it. Or at least they should have told you if it was leaking; it's pretty obvious, you can see it on the flywheel:

**gldfshkpr** · 11-22-2007, 11:08 AM

Quote:

Originally Posted by Dudesky

The main seal is not part of a clutch job, so I'm sure they would have told you if they replaced it. Or at least they should have told you if it was leaking; it's pretty obvious, you can see it on the flywheel:

I should haved looked more closely at the invoice before posting. This is a new purchase to me. All I've had done is an Inspection II. The invoice for previous owner's repair back this September reads like this...

"Remove transmission and replace clutch kit. Resurface flywheel and replace pilot bearing. Replace rear trans seals and flex disc. Replace trans mounts."

Thank you for using the proper term "pilot beaing". That's why I didn't remember seeing the term main seal, which is what I always went by with my other non-BMW cars.

**gldfshkpr** · 11-22-2007, 11:15 AM

Both lower timing cover gaskets were replaced May 2007.

**Dudesky** · 11-22-2007, 12:40 PM

Quote:

Originally Posted by gldfshkpr

I should haved looked more closely at the invoice before posting. This is a new purchase to me. All I've had done is an Inspection II. The invoice for previous owner's repair back this September reads like this...

"Remove transmission and replace clutch kit. Resurface flywheel and replace pilot bearing. Replace rear trans seals and flex disc. Replace trans mounts."

Thank you for using the proper term "pilot beaing". That's why I didn't remember seeing the term main seal, which is what I always went by with my other non-BMW cars.

No no, the pilot bearing and engine's rear main seal are two different things. That photo was just from another thread, that happened to be pointing to the pilot bearing. What I was really showing in the photo was the drip marks on the right. That is oil leaking out of the center from a bad rear main seal, which is actually located further back behind the pilot bearing.

**gldfshkpr** · 11-22-2007, 12:46 PM

Oh, I see. Well, the flywheel was resurfaced, does that mean the flywheel was taken off? That would have exposed the main, right? I suppose if the main seal was replaced, it would have shown up on the invoice.

If that is the cause, I guess I'll wait until the clutch needs replacing. That could be a while. It's a brand new clutch. Hmm... any other thoughts?

**94bmw325i** · 11-22-2007, 11:55 PM

when my 325 had a bad oil leak it was the oil filter housing.

**gldfshkpr** · 11-23-2007, 11:00 AM

Quote:

Originally Posted by 94bmw325i

when my 325 had a bad oil leak it was the oil filter housing.

Thanks. That should be fairly easy to spot. I'm getting some stands and a creeper today. I haven't even been under the car yet. I have tons to learn.