Author Topic: Major oil leak (Read 3423 times)

gearheadE30 · « **on:** November 21, 2007, 12:18:57 PM »

Well, after running at an autox for a day a few weeks ago, my car is now leaking a crapload of oil. In less than a month it has lost 1/2 quarts of oil. The leak appears to be on the front of the engine on the passsenger side right above the AC compressor. The oil almost looks like it is coming out of the profile gasket, but I'm pretty sure that that gasket only seals coolant passages. Any ideas on what might be leaking back there? The car runs great otherwise and still doesn't burn any oil, so I doubt that it is the head gasket. I had my mechanic look at it and he said the only way to tell where it was really comig from is to degrease the engine, drive it for a few days, and see where the oil is. The only other way would be to take off the AC compressor, which isn't that hard. Any ideas?

FL318is · « **Reply #1 on:** November 21, 2007, 03:22:36 PM »

Chain tensioner?

Vladi · « **Reply #2 on:** November 21, 2007, 04:25:03 PM »

Either profile gasket or cylinder head cover gasket.

gearheadE30 · « **Reply #3 on:** November 21, 2007, 09:08:19 PM »

I just replaced the cylinder head cover gasket, so that's the first think I checked. It's clean, so that's not it. It might be the tensioner, I didn't think of that. Just replaced that one, too.

Doesn't the profile gasket only seal the water passages on the front of the engine?

Vladi · « **Reply #4 on:** November 22, 2007, 12:40:38 AM »

Not really, it seals the chain section wich runs in oil. Part #4.
http://www.realoem.com/bmw/showparts.do?model=CG51&mospid=47454&btnr=11_2685&hg=11&fg=10

ApocolypseAutoEngineering · « **Reply #5 on:** November 22, 2007, 01:05:54 AM »

If you still can't find it there is a tint that you could put in the oil for couple of days that reacts to blacklight, its harmless to the motor. If you run on it for a day or two and shine a black light at it at night, then you have where your leak is. Another mechanic gave some to me when I had my old shop and it disappeared. I wish I could tell you what it was called but it sure save me a ton of headaches.

gearheadE30 · « **Reply #6 on:** November 22, 2007, 09:19:05 AM »

Cool, that's a pretty good idea.

Vladi: I replaced part number 4. I guess I had the wrong part name, because I was under the impression that the profile gasket was the other half of #4, which is in between the head and the timing chain rear case. There is no oil on the front of the engine, so I doubt that is it. If the rear half failed, there would be oil in the coolant and vice versa, which there is not. I'm a bit stumped here...

gearheadE30 · « **Reply #7 on:** November 23, 2007, 04:12:14 PM »

Ok, the leak is fixed. I didn't torque the tensioner to the right specs. Thanks for all the help guys!