Several things can go wrong with the oil pan in your 1999 Cavalier that can lead to the need for a replacement. Stripped drain plugs and impact damage from objects in the road are the most common problems, and replacing the oil pan can prevent damage to the engine caused by loss of oil from leaks or oil pressure from a pan that has collapsed around the oil pump pickup. Common hand tools are required and the average home mechanic can complete this repair in a few hours.
Disconnect the negative battery cable by unscrewing the battery cable bolt in the center of the cable end using an 8-mm wrench. The battery in the Cavalier is located in the driver-side front of the engine compartment in front of the air filter housing.
Place wheel chocks behind the rear wheels and set the parking brake securely. Raise the front of the car using a floor jack positioned under the front sub-frame, until the front wheels are off the ground. Place jack stands under each side of the sub-frame and lower the car onto the stands. Slide the floor jack out from under the car.
Place a drain pan under the oil pan, located on the bottom of the engine, and remove the drain plug. Drain the engine oil into the drain pan until it only drips. Reinstall the drain plug and remove the oil filter.
Remove the 10-mm bolts that attach the heat shield to the top of the exhaust pipe using a 10-mm wrench. Slide the shield out of the engine compartment. Remove the 15-mm bolts that attach the exhaust pipe to the exhaust manifold using a 15-mm socket, a long extension and a ratchet. Pull the exhaust pipe down for clearance when pulling the oil pan out.
Remove the two 15-mm starter bolts and the 10-mm rear starter support bolt using a ratchet and 15-mm socket. Allow the starter to hang from the engine. Remove the 10-mm bolts that attach the plastic inspection cover to the transmission, and lay the cover aside.
Remove the 10-mm bolts that attach the oil pan to the engine block and drop the pan down. Slide the pan past the exhaust and out from under the car.
Clean the gasket surface on the engine block with parts cleaner. Screw the four plastic alignment pins, supplied in the gasket kit, into the engine block at the four corners of the gasket surface. Align the gasket with the block and push the gasket onto the alignment pins.
Align the new pan with the engine block and push it onto the alignment pins. These plastic pins hold the gasket and pan in place while you install the pan bolts. Install the oil pan bolts and tighten them to 89 inch-pounds using a torque wrench. Remove the four alignment pins and install bolts in their place. Then tighten the final four bolts to 89 inch-pounds.
Reinstall the transmission inspection cover, starter, oil filter and exhaust. Fill the engine with clean oil and start it. Check for leaks before raising the car off the stands using the floor jack and removing the stands. Lower the car to the ground.
