Cylinder-head cover

Above the cylinder head, often under a cosmetic engine cover.

Its gasket seals oil inside; some designs also integrate crankcase-ventilation passages or hardware.

A protective lid on a moving mechanism.

Oil smell, visible seepage or ventilation faults may involve the cover, gasket or connected hoses.

Usually condition-based rather than a routine replacement. Lubrication, overheating and the exact engine affect wear.

Internal-engine work is usually labor-intensive. Diagnosis and the engine code determine the repair scope.

BMW petrol and diesel engines; petrol-only systems are identified individually.