Pontiac G6 2.4L 4-Cylinder, 3.5L, 3.6L, 3.9L V6 Repair Manual 2005-2009

• 2.4L DOHC Transversely-mounted four-cylinder
• 3.5L V6
• 3.6L V6
• 3.9L V6

GENERAL INFORMATION - ENGINE COOLING SYSTEM

The cooling system consists of a radiator, an expansion tank, a pressure cap (located on the expansion tank), a thermostat, electric cooling fans, various hoses and a belt or chain driven water pump.

The expansion tank is designed to store coolant and to separate any trapped air in the coolant. It has a pressure cap on top. The radiator on these models does not have a pressure cap. Warning: Unlike a conventional coolant recovery tank, the pressure cap on the expansion tank should never be opened after the engine has warmed up because of the danger of severe burns caused by steam or scalding coolant.

When the engine is cold, the thermostat restricts the circulation of coolant from the engine. When the minimum operating temperature is reached, the thermostat begins to open, allowing coolant to return to the radiator.

All models are equipped with a transaxle cooler, located inside the radiator, which cools the transaxle fluid. The transaxle is connected to the cooler by a pair of hoses; one delivers hot transaxle fluid to the radiator and the other brings the cooled fluid back to the transaxle.

For more information on transaxle oil coolers, refer to Chapter 7.

The vehicles covered by this manual are equipped with hydraulically operated front and rear brake systems. The front brakes and rear brakes are disc type. Both the front and rear brakes are self adjusting. The disc brakes automatically compensate for pad wear.

The hydraulic system consists of two separate circuits. The master cylinder has separate reservoir chambers for the two circuits, and, in the event of a leak or failure in one hydraulic circuit, the other circuit will remain operative. A dual proportioning valve in the circuit provides brake balance between the front and rear brakes. Models that are equipped with ABS (see Section 2) do not require pedal effort.

• Introduction: Vehicle identification numbers. Buying parts. Safety. Maintenance techniques. Chemical and lubricants, and more.
• Tune-up and routine maintenance
• Four-cylinder engine
• 3.5L and 3.9L V6 engines
• 3.6L V6 engine
• General engine overhaul procedures
• Cooling, heating and air-conditioning systems
• Fuel and exhaust systems
• Engine electrical systems
• Emissions control systems
• Manual transaxle
• Automatic transaxle
• Clutch and driveline
• Brakes
• Suspension and steering systems
• Body
• Chassis electrical system
• Wiring diagrams