How to Troubleshoot the Cooling System in a Pontiac Grand Prix

Diagnose cooling system problems by understanding how the system works. In simple terms, coolant picks up heat when it goes through the engine and releases heat in the radiator. Cooling devices function by circulating antifreeze, containing it or controlling its temperature. Troubleshoot the cooling system in a Pontiac Grand Prix by inspecting cooling system devices. These steps relate to most model years.

Instructions

1

See if your water pump is leaking. The water pump pushes coolant through the engine, radiator and heater core. A faint antifreeze smell or spots of coolant under your Grand Prix when parked for a short time indicate a worn out water pump.

2

Look for cracked, collapsed, leaking or dry hoses. Check upper and lower radiator hoses, heater and bypass hoses and manifold coolant hoses. Your upper hoses for instance, measure about 2 inches wide and carry coolant between the radiator and engine. Damaged hoses lead to cooling system problems.

3

Check the antifreeze amount. Overheating and other cooling problems can result from low coolant levels. In this case, put DEX-COOL extended life engine coolant in the expansion tank reservoir. This applies to the 3100 V6 (CODE J) and 3800 V6 (CODE K) engines.

4

Drain and flush the cooling system to help diagnose cooling system problems. Make certain to dispose drained antifreeze properly because the coolant's sweet smell attracts animals and small children. Ingesting the poisonous liquid can be deadly.

5

Inspect the radiator cap for signs of wear and tear. For example, a damaged cap could show corrosion. Ask a mechanic to use a pressure tester or an adapter to inspect the cap's pressure rating and operation. Promptly replace a defective cap.

6

Wash and gently scrub the front of your radiator. When you drive, dirt, rocks, leaves and other debris suck into the fins of your radiator causing overheating. Clean it with soapy water, a soft nylon brush, and a garden hose to rinse.

7

Test the thermostat for sticking. Pinpoint a stuck thermostat are constant low temperature readings or peaks between high and normal temperatures. Your thermostat, the spring-loaded valve that reacts to coolant temperatures, is usually located inside the housing on the engine side of the upper radiator hose.