The water pump is part of the vehicle cooling system that transfers water from the engine, where it helps regulate temperature, to the radiator. A bad water pump can cause vehicle overheating and can damage the engine, leading to costly repairs. You can replace the water pump in your 1999 Chevy Malibu yourself with an assortment of common tools. Water pump replacement in the 2.4-liter Chevrolet engine can be time-consuming and complex, as you must remove one of the engine motor mounts.
Park your Chevy Malibu on a level surface. Place the vehicle in "Park" if automatic or in gear if manual. Set the emergency brake.
Open the hood and prop it up using the hood support rod. Put on safety glasses.
Disconnect the negative battery cable from the battery terminal using a wrench.
Slide a floor jack under the front crossbeam and lift the front of the vehicle. Place jack stands beneath the front jack points, directly behind the front wheels. Lower the floor jack until the vehicle rests on the jack stands. Remove the floor jack.
Place a coolant drain pan beneath the radiator (located near the front of the engine). Remove the drain bolt on the bottom left side of the radiator using a wrench and allow the coolant to drain from the radiator.
Drape a soft cloth over the floor jack and place it beneath the engine oil pan. Lift the jack up until it rests beneath the oil pan.
Remove the bolt securing the engine mount on the left rear side of the engine using a wrench. Remove the motor mount.
Locate the water pump, below the exhaust manifold, on the left side of the engine.
Disconnect the water pump hoses from the water pump by compressing the wire hose clamp using a pair of pliers and then pulling the hose directly away from the unit.
Remove the bolt in the center of the crankshaft pulley using a wrench. Insert a flat-head screwdriver into the opening in the center of the crankshaft pulley to hold it steady while you remove the bolt. Remove the timing chain from the pulley on the water pump. The engine timing chain drives the water pump in the 2.4-liter Malibu engine.
Remove the four bolts holding the water pump to the engine using a wrench. Remove the old water pump.
Scrape the mounting surface of the water pump clean of any old gasket debris using a flat spackle tool or razor blade. Remove as much of the old gasket as possible.
Install the new water pump gasket on the mounting surface and then install the replacement water pump. Make sure you line up the bolt holes on the water pump with the bolt holes on the engine mounting surface.
Install the water pump mounting bolts and tighten to 18 foot-pounds of torque using a torque wrench.
Follow the removal steps in reverse to reassemble the vehicle parts. Refill the radiator with approximately 2 3/4 gallons of Dex-Cool coolant.
