Plenty of pressure under the bonnet

High temperatures, enormous internal pressure in the crankcase, hot oil and fuel vapours – there is always plenty going on under the cylinder head cover of a running combustion engine, also known as the rocker cover. It’s no wonder that the components, which are mostly made of plastic nowadays, show signs of wear and tear after high mileages. Material cracks appear, seals become hard, brittle and also crack. The possible consequences: Oil loss and/or rough idling.

Frequent short journeys also put a strain on the cylinder head cover. In the course of time, they cause the crankcase ventilation system and its valves and hoses to become silted up. This increases the pressure in the crankcase, which in turn can cause serious damage to various parts of the engine.

Before the pressure under the cover becomes too high and the first signs of (material) fatigue appear, it is better to replace the cylinder head cover. AIC currently has 77 items with 5,600 applications in its range, many of which also include the valves.

Incidentally: If the cylinder head cover is defective, besides replacing it, it’s always worth taking a look beyond this component. For example, a non-functioning water pump, a stuck thermostat or too low a coolant level can lead to overheating, which often also affects the cylinder head cover.