[riccume]

Hello there. Maybe somebody has encountered this issue before?
Frequently, about 5 minutes after I start the car, I get a strong burnt smell from the vents. It doesn't happen every time I start the car but when it happens, it is always about 5 minutes after I start the car.
If I switch off the air recirculation (I normally leave it on auto) the smell goes away very quickly and doesn't come back when I switch the air recirculation back to auto.
The smell is similar to the one of burning plastic. No smoke.
A couple of times, I managed to stop as soon as the smell started, open the bonnet and have a sniff around the engine bay, including under the wheel arches, but the smell isn't strong at all outside the car so no idea where it is coming from. Again, no smoke.
The car is a 2004 X3 3.0i.
Any ideas what it might be? Thank you!

[1Bigwave]

Are there any signs of Oil dripping from the Valve Cover onto the Exhaust Manifold? If so, it is possible your Valve Cover Gasket needs replacement or the Valve Cover could be cracked or warped?

[bimmerman14]

Sounds like possible leak from valve cover