OEM 2003 GMC Envoy Thermostat

2003 GMC Envoy Thermostat Parts and Q&A

• Q: How to replace the thermostat on a 4.2L engine on 2003 GMC Envoy?

  A: To replace the Thermostat of 4.2 engine first extract needed coolant from the Radiator and after that extract the generator. It can be done using the hose clamp pliers (J 38185) to loosen the outlet hose clamp at the Thermostat Housing and getting the outlet hose out. Then, unfasten the bolts of the Thermostat Housing and unfasten the housing from the engine block. Clean all Thermostat Housing panels and sealing surface of engine block. Lock the temperature sender into place in the Thermostat Housing while gripping the housing, without working on the water inlet to the engine block, following the fastener notice as required for a correct fix. Tighten the Thermostat Housing bolts, until it reaches 10 nm (89 inch lbs.). Apply engine coolant to lubricate the inner diameter of the Radiator hose and slide the outlet hose onto the Thermostat Housing and tighten it using the clamp. Uninstall the generator, refill the cooling system with the given coolant and concentration, and last, check all sealing for leakage after starting the engine.