Circuit/System Testing

WARNING: This page is about a different car, the 2007 Pontiac Montana SV6, 2007 Chevrolet Uplander, and 2007 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.

Test the thermostat for correct operation. Refer to Thermostat Diagnosis .
Test the engine cooling system for overheating. Refer to Engine Overheating .
Inspect the water pump and coolant flow for correct operation. Refer to Water Pump Replacement .
Inspect the engine mechanical for worn/leaking/cracked cylinder heads or engine block. Refer to Coolant in Combustion Chamber and Coolant in Engine Oil .