Thermostat: Service and Repair

Thermostat Replacement (4.3L)

Removal Procedure

1. Remove the air inlet duct.
2. Remove the necessary coolant from the radiator.
3. Remove the upper radiator inlet hose.




4. Remove the coolant outlet bolts.




5. Remove the coolant outlet from the lower intake manifold.
6. Remove the thermostat gasket.




7. Remove the coolant thermostat.
8. Clean all the sealing surfaces of the coolant outlet.
9. Clean the sealing surface on the lower intake manifold.

Installation Procedure

Important: In order to prevent leakage, thoroughly clean all parts and sealing surfaces.




1. Install the coolant thermostat in the lower intake manifold




2. Install a new gasket (if used). Otherwise, place a 3 mm (1/8 in) bead of RTV sealer) at the groove on the coolant outlet sealing surface.
3. Install the coolant outlet on the lower intake manifold.




4. Install the attaching bolts.
Tighten coolant outlet bolts to 19 N.m (14 lb ft).
5. Install the radiator inlet hose.
6. Fill the cooling system with specified coolant and concentration.
7. Inspect all sealing surfaces for leaks after starting the engine.