318i squealing from back of motor??HELP.

[Obsessive Bhvr]

Hi everyone,I'm a new member and I'v never done this before,so apologies in advance.I was hoping that someone would be able to tell me why my 318i is squealing like a pig.

[Obsessive Bhvr]

This is my first BMW and I really like the car. My problem is a squealing noise that seems to be coming from between the motor and tranny. It doesnt make the noise when in gear accelerating, But at idle its always there after the tranny warms up. if in nuetral you can rev up and the noise does not change. The nearest I can tell it is some kind of vaccum leak because after you shut the engine off and it has stopped turnning you can still here it for a few seconds and it sounds like someone pinching the end of a balloon shut. I heard someone say it might be a rear main seal worn and sucking air. but I dont seem to be losing any oil and the engine still makes good vaccum. Any help would be greatly appreciated..Thanks

[mikese36]

Sure your belts are ok?

[Flat Broke]

Hey there Obsessive,
I had a 96 GM with a 3800 V6 that made the same sound, turned out to be vacuume comming through the rear seal. Drove me nuts trying to find it and several mechanics swapped out several parts. But then I had a guy drop the inspection cover under the flywheel(It was an automatic trans) and spray WD40 at the rear main seal. The sound would stop until the WD40 dried out.(About 3-5 minutes) A quick way to check is by removing the oil fill cap and place your hand over the fill tube. We fixed it by restricting the flow through the PVC valve. I don't think it was a correct fix, and for that old Buick I really didn't care, I was just happy to get rid of the squeal... Hope this helps.
FB