The Nissan Sentra is known to develop oil leaks at some point. As a result you will need to perform maintenance on it. One way to ward off an oil leak is to change the valve cover gasket. You can perform this preventive measure yourself.
Disconnect the battery cable from the negative battery terminal. Remove the spark plug wires off the spark plugs and separate them from their brackets. Remove the PCV hoses and the throttle cable from its brackets, clearing them from the area that you need to work in. Remove the ignition cool wires.
Release the bolts in sequence. Remove the valve cover and the old gasket. Clean the gasket seating area and the engine head. Using a gasket scraper, remove all traces of the old gasket, and then clean any remaining oil from the surfaces. Apply sealant to the gasket and engine head around the valve cover.
Place the new gasket in the gasket seating area. Replace the valve cover gasket. Tighten the valve cover gasket bolts in sequence.
Reinstall the ignition coil wires. Put the PCV hoses back. Reattach the throttle cable to its brackets. Reconnect the battery cable.
Check the oil level by pulling the oil stick out and wiping the oil stick on a paper towel and then reinserting and removing it. Add oil to the car, as needed. Start the car and run it, allowing the oil to move to the top of the head.
