This generation of Nissan Sentra is particularly prone to oil leakage, and one of the prime locations for a leak is the valve cover gasket. A mechanic will charge $100-$200 to change the gasket, but the gasket costs only $30, so it is possible to save a lot of money if you do it yourself.
Step 1
Disconnect the battery cable from the negative battery terminal.
Step 2
Remove the items which are in your way: Pull the spark plug wires off the spark plugs and remove them from their brackets, remove the PCV hoses, and remove the throttle cable from its brackets and position it out of the way.
Step 3
Loosen the fasteners in the order indicated in the picture. Carefully remove the valve cover from the engine head.
Step 4
Remove the gasket from the valve cover.
Step 5
Thoroughly clean the mating surfaces of the valve cover and the engine head. Use a gasket scraper to remove all traces of old gasket, and then use laquer thinner or acetone to clean any remaining oil from the surfaces.
Step 6
Apply RTV silicone sealant to the gasket and engine head around the cutout areas of the valve cover.
Step 7
Lay the new gasket in the groove in the valve cover.
Step 8
Reinstall the valve cover with its new gasket on the engine head.
Step 9
Tighten the fasteners in the order indicated on the above diagram.
Tips
- If the valve cover does not come off the engine head easily, use a block of wood and a hammer to bump it in an attempt to jar it loose. If absolutely necessary, you may slip a flexible putty knife between the head and the cover to break the seal.
- If you purchased a valve cover gasket kit, don't forget to replace the small rectangular gasket and the spark plug seals as well while you have the valve cover off the car.
- You may take this procedure as an opportunity to clean off all the oil which has leaked all over the engine. It may be helpful to remove the aluminum exhaust manifold cover and clean oil off the exhaust manifold.
- Don't forget to re-attach the PCV hoses, throttle cable, and spark plug wires.
Warnings
- DO NOT attempt to pry the cover off the head using a screwdriver or chisel. Doing this could mar the mating surfaces, leading to irreparable oil leaks in the future.
- Be very careful not to introduce foreign matter into the engine. If you get anything (dirt, metal shavings, bits of old gasket) into the engine, it may be circulated throughout the entire engine in the oil, and can quickly degrade components.
- DO NOT over-tighten the valve cover fasteners. On the 1.6-Liter engine (the one depicted in the photographs), the fasteners need only 17 to 34 in-lbs of torque.
Things You'll Need
- Replacement gasket
- RTV Silicone Sealant
- Phillips-head screwdriver
- Lacquer Thinner or Acetone
- Gasket Scraper
- Lots of rags or paper towels
- Optional: Haynes manual or other vehicle maintenance manual
