BMW F10 N57 valve cover leak

The cover can develop a hairline crack and warp, so the gasket leaks. The crack typically forms at the seam between the breather channel and the cover. Replacing only the gasket is usually not enough; the whole valve cover is replaced.

Oil leaking from the valve cover runs onto the turbos and the hot exhaust manifold and burns. If the smell continues after the cover is replaced, check the turbo oil return pipe, the turbo seals and the breather pipe, as they leak too.

Buy an original cover, because an aftermarket cover may sit crooked and leak again. The gasket is chosen according to the cover's production date. Always replace the bottom gaskets, clean the injector seats and do not mix up the order of the injectors. The cover bolts are tightened in sequence to 9 Nm.