Cylinder head and sealing

Valve covers

Valve covers (cam covers) that close the top of the cylinder head over the camshafts and the valvetrain, hold the oil in and keep dirt out, with their gaskets and the seals of the spark plug wells, for European and Japanese passenger cars, identified by OE reference.

MONTTRON valve cover: a black plastic cam cover for a four-cylinder engine, with the four spark plug wells, the oil filler cap and the breather connection

The valve cover, also called the cam cover or rocker cover, closes the top of the cylinder head over the camshafts, the tappets and the valve springs. It holds the oil that lubricates the valvetrain inside the engine, keeps dirt out, and carries the oil filler neck, the breather connection and on many engines the crankcase ventilation valve with its oil separator. Older covers are pressed steel or cast aluminium; most modern covers are moulded plastic, with the spark plug wells passing through them and a moulded gasket in a groove.

Covers fail in two ways. The gasket and the seals of the spark plug wells harden with heat cycles and lose their spring, so oil weeps down the head onto the exhaust or fills the spark plug wells and drowns the ignition coils. And plastic covers warp or crack, at the bolt bosses, at the oil filler or where the ventilation valve sits; when the membrane of an integrated ventilation valve tears, the engine idles roughly, whistles or starts using oil, and no gasket will cure it.

MONTTRON valve covers are made to OEM-compliant quality and as aftermarket spare parts: the outline, the bolt pattern and the gasket seat of the original, so the cover seals on the original head with the original fasteners. The materials are tested for durability and temperature resistance.

The range covers European and Japanese passenger cars. Each reference is identified by the OE number of the original part; send that number and the vehicle identification number (VIN) and we confirm the matching MONTTRON reference.

For availability and OE cross-references, contact us by email.

Frequently asked questions

Why does oil leak from the valve cover?
Because the gasket has hardened and shrunk with heat, the cover has warped, or the bolts have lost their tension. Oil then runs down the outside of the head onto the exhaust manifold, where it burns and smells, or into the spark plug wells, where it soaks the coils and causes misfires.
What is the ventilation valve on the cover?
On many modern engines the crankcase ventilation valve and its oil separator are built into the valve cover. When its membrane tears, the engine draws air through the cover, idles roughly, whistles or uses oil, and the cover is replaced as a unit.

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