Hello,
I have a 94 325is. It also is leaking from the back of the housing. After removing the the Air filter housing and degreasing the engine. I had my wife start the car while I looked with a flashlight and drop light.
I noticed on the back of the housing there are two caps, each held in by a snap ring. Both were leaking and running down the side of the engine block on the oil pan and crossmember. I'm a mechanic in the Army (11 years), so I decided to remove it myself.
Not bad; had to take off the air filter housing, belt, and alternator to access all the bolts to remove the housing. A total of 6 bolts and 1 hose; easy to access.
Once I removed the housing I took a flat tip screwdriver and a pair of needle-nose pliars and popped off the snap-rings. The caps are recessed inside the housing, so I took my pliars and pulled the caps out.
Well around each cap is an o-ring; and one was so fragile from the age/heat that it just crumbled when I pulled it out. The other o-ring was still located around the cap; it was hardened from the heat. When I tried to pull the o-ring off the cap it cracked in half.
A new housing is about five bills. I found a used one on ebay for about $75 (probable with old o-rings). I found some cheap parts for it on maximumautoparts.com. I ordered the oil leveler O-rings and the Oil Filter Stand Gasket (which was also fragile and garbage from the heat). Which goes between the housing and engine block when you put it back together.
Not sure if these o-rings will fit the two caps; but if not, I'm sure the part stores have an o-ring kit.
The only thing I question is whether or not this will fix the leak; if these valves are bad this may be contributing to the leak. I'll take a chance and use my experience. Once I get the parts I can have it back together in about an hour and a half. Not sure if this helps anyone; but if you have any experience with this your knowledge will be apprciated.
Thanks,
Soldiers BMW
Also, replacing the valve cover gasket. If anyone is interested in how-to.... Parts kit is about 28 bucks. Order the rubber washers also; about a buck. Web site listed above..
