Jeep 53010552AA Thermostat

If the engine is running hot and the upper radiator hose isn't hot, this typically indicates that the thermostat is stuck closed. Replacing the thermostat is necessary.

Disconnect the battery cable and drain the cooling system. On 3.6L engines, remove the air filter housing. Follow the upper radiator hose to the engine to locate the thermostat housing. Loosen the hose clamp and detach the hose from the fitting. If it's stuck, use adjustable pliers to twist and break the seal. If the hose is old or deteriorated, cut it off and install a new one. If the fitting is deteriorated, the thermostat housing cover may need to be replaced. Remove the bolts and detach the housing cover, tapping it with a soft-face hammer if necessary. Note how the thermostat is installed and remove it. Clean the housing and cover, then install the new thermostat with the correct end facing up. Apply RTV sealant to both sides of the new gasket and position it on the housing. Install the cover and bolts, then reattach the hose and tighten the clamp securely. Refill the cooling system and start the engine to check for leaks and proper thermostat operation.