1999 Nissan Sentra Valve Cover Gasket Replacement Cost

A vehicle can still be driven with a leaking valve cover, but the leaking oil will cause other problems over time. Spark plug wells can fill with oil, causing a misfire. Oil dripping on coolant hoses will cause them to become soft and eventually burst. And the smell of burning oil will become more noticeable in the cabin.

Repair intervals vary greatly by vehicle and driving conditions. The valve cover gasket does not wear like a tire or a ball joint, but eventually the gasket's rubber or cork will degrade to the point where it leaks. 

It is easiest to spot oil leaks when they are new or fresh. The technician may clean the fluid around the leak and direct you to come back later to confirm where the leak is coming from. With more progressed oil leaks, the technician will also add a dye to the oil. After the vehicle has been driven with the dye, a UV light will be used to pinpoint the leakage and recommend repair.

Components such as spark plug tube seals and grommets can also leak oil, which can be mistaken for a leaking valve cover gasket. The seals and the valve cover gasket should always be replaced together. Some valve cover gasket kits may not include these seals and grommets, in that case the RepairPal estimate would not include them either and adding them could result in an additional cost for parts and labor to the customer.

The technician will remove the valve cover, remove the old gasket, and clean all gasket surfaces before installing the new valve cover gasket. On some engines, removal of the intake manifold, or other major parts may be required in order to access the fasteners on the cover. After completion, the area will be checked for leaks.

Using high-quality valve cover gaskets will reduce the chance of recurring leaks and additional repairs.