Oil Separator Valve?

[dietzgw]

I've read lots on this forum about the oil separator. Usually accompanied by lots of loud noises and screeching from the engine.

Today my wife was driving our '96 740iL and it started making that noise. She called me and let me listen to it over the phone and it was quite loud, almost sounding like a fan belt screeching. However, when I got home tonight I fired it up and - no noise! It did smoke for awhile though. A very light colored smoke that looked like oil smoke and smelled like oil smoke. After it idled for awhile the smoke cleared out. I took it out for a drive and everything seemed normal. I stood on it and all was well until it shifted into 2nd gear and then it blew out white smoke out of both exhaust pipes. I backed off and it quit smoking. It runs and idles fine. I have pulled the dip stick and there is no rushing of air.

Is it possible that the oil separator valve is only partially broken? Or are these symptoms caused by something other than the oil separator valve?
Gary Dietz
1996 740iL - Aspen Silver

[dietzgw]

Didn't get an answer back on this forum, but just in case someone else is searching for the same answer: Turns out that it was indeed the oil separator valve. It can indeed fail with intermittent noise rather than the "full time" screeching noise that is usually reported. Only made the noise once and then quit. But the other symptoms that I described persisted. Changed out the valve and all is well.
Gary Dietz
1996 740iL - Aspen Silver

[cris e]

hi Gary, how much did you pay for the repair, or was it DIY? I have the same symptom and I'd like to try i out. thanks much!

[dietzgw]

I'm not sure what it cost, as I had some other things done at the same time (new valve cover gaskets, etc). I do know that he had done this several times so was able to change it without removing the intake manifold, which is the standard method. If you know where the bolts are, have small and flexible fingers, and can work without seeing what you are doing, you can do it without removing the manifold. I think he said it was about 4 hours of labor for the valve, but I can't say for sure. The guy I use is a certified ex-BMW mechanic who now runs the automotive tech program for a local University.
Gary Dietz
1996 740iL - Aspen Silver

[cris88]

thanks Gary, i managed to remove the intake manifold cover, took me 3 hours with very hard to reach areas, specially the 2 bottom bolts. i did notice small oily part at the bottom but the entire cover seem clean with no sign of wear and tear. the bolts have already been replaced with 10mm so i'm guessing this was already replaced before i got it 3 years ago. is there something inside that needs to be removed aside from the gasket? i was thinking of replacing just the gasket and put some good silicone with it. thanks!

1997 740iL Silver

[dietzgw]

Are you still talking about the Oil Separator Valve? If so, I don't think you are in the right area. The OSV is at the back of the engine, tucked in under the firewall. You can't see it or the bolts. Have to feel for them by hand. Also has a hose attached to it. When you remove it, it is about 5 or 6 inches square and about an inch thick.
Gary Dietz
1996 740iL - Aspen Silver

[cris88]

using your posting and all, got it installed just few hours ago, no more whining and growling, drives nice.
thanks much

[claudio512]

Your imposition and expectations are preposterous, and be happy that someone in the forum did responded to your message. Responding is done in volunteer basis, and if available. Perhaps, you should be appointed to be forum monitor and whenever anyone post message you shall reply “ipso facto” or immediately to their S.O.S., requests… having said that... lets be less arrogant about as to whom or when one has to respond. These comments may not be call for but imposition is not one’s obligation other than a volunteer and spontaneous response if has knowledge of the issue, and if available to respond. Lets be courteous and use common sense. LOL "Keep Right, Pass Left. It's the Law."

[AprilGoose]

[claudio512]

while some are on top... others are on the bottom... I learned that from my mother, and she was top-exec for Northwest Airlines.

"Keep Right, Pass Left. It's the Law."