klepdeksels

Klepdeksels, in automotive Dutch, are the covers that enclose the valvetrain on top of an internal combustion engine. They sit on the cylinder head and form a barrier between the moving camshafts, rocker arms and valve springs and the outside world, while also keeping lubricating oil contained within the engine.

The primary function is to protect the valvetrain from dirt and to seal oil inside. They often also provide access for oil filling and crankcase ventilation; many models include an oil filler cap and a PCV (positive crankcase ventilation) valve or ports integrated into the cover.

Klepdeksels are usually made from stamped metal such as aluminium or steel, though some modern engines use plastic or composite covers for weight reduction and styling. They are fastened to the cylinder head with bolts or screws and sealed with a gasket, commonly rubber, silicone or cork-based.

Maintenance involves inspecting for oil leaks around the gasket and corners, replacing the gasket when removing the cover, and ensuring any PCV connections are clear. Damage to the cover, such as warping or cracking, can cause oil leaks or misalignment of the valvetrain.

In Dutch automotive terminology, the term klepdeksel corresponds to the English "valve cover". It is a standard component across most petrol and diesel engines and also appears on many motorcycle and small-engine designs.