The Chevrolet Malibu is manufactured with a pressurized coolant system that uses a finned radiator to cool the engine. This radiator is made of aluminum and copper, and is prone to corrosion and failure due to the acidic nature of the coolant fluid. The average backyard mechanic can replace a Malibu radiator in about an hour.
Place a drain pan underneath the front of the Malibu, then turn the radiator petcock counterclockwise with a bare socket wrench. The plastic valve will open and allow the coolant to drain from the radiator. Open the radiator's cap to relieve the pressure and allow all coolant to drain out.
Remove the upper and lower coolant hoses by pinching their hose clamps with vice grips. Some models will have screw-type hose clamps that will release when the screw is turned counterclockwise. The hoses pull off, and can be left in place. Remove the fan and fan shroud on electric fan models; on mechanical fan models, only the fan shroud must be removed. Both types unbolt with four hex-head corner bolts, and the electric fan can be unplugged from the wiring harness at the adapter close by. Older models will also have transmission cooler lines (dual-core radiator) that run into line bolts on the top and bottom of the radiator housing. Line bolts can be removed with open ended wrenches or a line wrench, turned counterclockwise.
Remove the bolts at the top of the radiator mount by turning them counterclockwise. The mount, or mount plate on some models, will release the radiator. Slide the radiator straight up and away from the engine. Position the new radiator at the top of the channel, then slide it into place. Tighten the mount bolts in a clockwise direction to secure the radiator.
Replace the fan shroud (and electrical fan, if applicable) by tightening its bolts in a clockwise direction and reconnecting the fan's adapter plug. Reconnect the steel transmission lines by tightening their respective bolts. Reconnect the coolant hoses and tighten or secure their hose clamps, being sure to position the clamp over the radiator input/output nipple. Refill the radiator with coolant, and top off the transmission if required.
