Burning smell while idling... - The Unofficial BMW M5 Messageboard (m5board.com)

Mtechnik540i · 1st January 2008, 06:03

Just replaced the valve cover gasket, and it seems that if the car sits for any prolonged period of time idling (which is rare), there seems to be a little bit of a burning smell, of which you can smell if the vents are open inside the car.

Popped the bonnet/hood and the smell seems to be mostly contained to the middle area close to the firewall.

I mentioned we replaced the valve cover gasket, but I've smelled new/fresh gaskets when they get hot, and this smells different. Along with this, you smell the front part of the valve cover and there's virtually no smell at all, it's pretty contained to the back of the motor/engine bay.

Any idea fellows?

TIA,

farrell · 1st January 2008, 12:08

Occasionally, you do get a faulty valve cover gasket.
They then leak from the back corner of No6 cylinder.
Rare though.

Would suggest degreasng the area.
It may just be pooled oil that sploshed out on the manifold headers
when doing valve clearances etc.
Run the car as before & inspect from above & below.
See how far up the oil comes from.
Most oil leaks in this area are down to the "O" ring on the end of the
main oil drain return pipe from head to sump or cam chest hermetic
gasket breaking up which is common.

Cheers
Farrell