This spring, after having my BMW 2002 garaged for the winter, I noticed that the interior of the car was filling up with exhaust fumes. I started searching for a leaky muffler or hole in the trunk of the car which would have been leaking exhaust fumes into the interior.

Failing to find any holes, I turned to the engine compartment. It turned out that the rubber hose attached to the valve cover and which is normally connected at the other end to a PVC valve and carburetor (allowing the carburetor to re-burn the fumes accumulating under the valve cover) was no longer attached to a PVC valve (Sometimes this occurs if OEM carburetor was replaced).

In fact, it was laying across the top of the valve cover with it's open end pointing toward the radiator fan. The fumes coming out of the hose were therefore being directed by the fan right back into the engine (and passenger) compartment.

The solution - redirect the open end of the hose between the firewall and rear end of the engine (away from the radiator fan), and back towards the ground. An easy fix!

Author: Ron Bass