The 3.1 L engine of Chevrolet Malibu may action discontent with coolant leaks. The source of the problems is the intake manifold gasket. The original equipment gasket may not seal the mating points of the intake manifold and the cylinder head.
Two types of leaks occur whenever the intake manifold gasket fails. An internal leak occurs when the coolant mixes with oil. The oil will appear to milky white in color. A second type of leak is the external leak. Coolant will stream on the side of the engine block and on the ground under the car.
The engine undergoes a heating and cooling cycle.The 1999-2003 Chevrolet Malibu uses General Motors's extended life coolant called Dex-Cool. This coolant product is orange in color. Dex-Cool corrodes the intake manifold gasket from the inside. The plastic material around the coolant manifold port breaks down and, as a result of this wear, a leak may appear.
After a set number of heating and cooling cycles the gasket will not assure the proper mating of the intake manifold and the cylinder head. When the mating parts are misaligned, an internal or external leak will occur.