The cam cover is a removable, protective cover made of metal which is fixed to the top of the engine by the head gasket (which is usually made from either rubber or cork) and together they act as a sealant, closing up the top end of the engine.

The cam cover effectively keeps the oil required to lubricate the engine inside where it belongs and is needed, while also preventing dirt, water and debris from entering the engine compartment.

Leaking oil, oil seeping into the spark plug wells, the smell of oil and a build up of dirt around the cam cover are all signs that the cam cover could have malfunctioned and may need to be replaced. This small part has a big role to play and if faulty and left unaddressed could lead to damage to the engine. A faulty cam cover will lead to the car leaking oil, which can have many knock on effects, but primarily the engine won't be lubricated enough which can have fatal results. 

It's not unusual for this part to require replacement. Subjected to extremely high temperatures the cam cover will eventually wear down and break. The cam cover is the ideal replacement part, specifically designed for the make and model of your vehicle.