The Malibu reappeared in Chevrolet's lineup in the 1997 model year -- Chevrolet originally discontinued the Malibu after 1983. The 2001 Malibu came fitted only with a 3.1-liter V-6 that used Dex-Cool coolant to keep the engine at an acceptable operating temperature. There are five common problems that cause the 2001 Malibu to overheat, including one technical service bulletin.
The 2001 Malibu's 3.1-liter engine has a cooling fan assembly mounted to the radiator to help lower the coolant temperature. The fan is made from hard plastic and has an electric motor that engages as needed. If the fan breaks or the electric motor fails, the Malibu will overheat. When this occurs, you may experience overheating only when idling. Once the Malibu starts moving, cool air flows over the radiator, lowering the coolant's temperature.
The 2001 Malibu has a thermostat to regulate the flow of coolant from the engine to the radiator. This valve starts to open at 189 degrees F to allow the coolant to start flowing from the engine to the radiator. At 207 degrees F, the thermostat opens fully, allowing the coolant to flow almost unrestricted to the radiator. If the thermostat fails and sticks closed, the Malibu will overheat.
The Malibu's engine has a series of passages that route coolant through the engine block and cylinder head. Over time, the cooling system can rust, due to incorrect coolant mixture or congealment from poor maintenance. These two issues can cause blockages in the cooling passages, which restrict the coolant flow and can lead to overheating. One way to prevent this is to follow Chevrolet's recommendation of power flushing the cooling system every 5 years or 150,000 miles.
The Malibu's cooling system is supposed to be completely sealed. If the coolant level is below the specified 3-1/2 gallons of Dex-Cool coolant, the Malibu's cooling system cannot absorb the heat from the engine. To keep the system sealed, Chevrolet installed rubber or cork gaskets between components. On April 8, 2008, Chevrolet released a technical service bulletin stating that the lower intake manifold gasket may fail, causing a nearly undetectable coolant leak. Chevrolet updated the intake manifold to improve its sealing qualities and prevent this leak from reappearing. The coolant can also leak from the radiator, radiator hoses, heater hoses, heater core and engine block.
The 2001 Malibu's cooling system has a belt-driven pump on the front of the engine that circulates coolant through the engine. When the fins on the water pump break or the bearing fails inside the water pump, the pump can no longer effectively circulate the coolant. When this happens, the Malibu will overheat.
