How to Change a Head Gasket on the 2001 Nissan Sentra

Disconnect the negative cable from the battery. Jack up the front of the vehicle and support with jack stands. Remove the right front wheel and the front right inner fender splash guard. Unfasten the right engine side cover and remove it. Drain the coolant into a pan by loosening the drain plug located in the engine block and the petcock drain valve in the bottom of the radiator. Unbolt the fasteners holding on the generator and move the generator to loosen the belt. Remove the generator and the drive belt. Unclamp the air duct that runs from the air cleaner to the intake manifold and remove it.

Loosen the bolts securing the power steering pump and remove it and the drive belt. Remove the water pump pulley by loosening the bolt in the center with a socket. Unplug the engine wiring harness and set it aside. Remove the fuel supply hoses and the regulator. Unplug any sensor wiring connecting to the cylinder head. Be careful not to break the plastic wiring clips. Remove the power brake vacuum booster hose and all of the power steering hoses. Remove the spark plug cables and all of the spark plugs.

Remove the rocker cover bolts starting in the center of the cover at the front of the engine then remove the one in the rear. Skipping the bolts in the four corners of the cover, remove the bolts from the front to the back. Remove the rocker cover bolts in the four corners. Loosen the four bolts securing the intake manifold supports and remove them. Remove the water pipe assembly at the front of the engine. Turn the engine over by hand until the piston closest to the front of the engine is at top dead center of its compression stroke. Feel for the piston rising through the spark plug hole. You can observe all of the valves are closed on the compression stroke.

Rotate the engine until the mating mark on the camshaft sprockets are in position. The mating mark is located on the outer part of the sprocket just under the timing chain. When looking at the front of the engine, the mark on the left sprocket should be at the 10:00 position, and the right side should be at the 1:00 position. Remove the cam chain tensioner by unbolting it, and remove the distributor. Apply a paint mark between the camshaft sprocket index marks to the cam chain. This is where you will install these parts when re-assembling. Remove the timing chain sprockets by unbolting them.

Mark the camshafts so that they can go back in their original position and remove them. Remove the heater hoses and the front oxygen sensor. Unbolt and remove the exhaust manifold cover and the EGR tube. Remove the exhaust manifold bolts working from the outside in and remove the manifold. You may need to tap it with a hammer to loosen it. Unbolt the outside cylinder head bolts. Starting at the outside of the cylinder head rear, then the outside front. Work inward from there. Remove the cylinder head with the intake manifold assembled to it. Clean and remove all of the head gasket material. Install the new head gasket on the engine and reverse the procedure to install.