OEM 2005 Cadillac STS Thermostat Housing

2005 Cadillac STS Parts Questions & Experts Answers

• Q: How to Replace the Thermostat Housing (LH2) on 2005 Cadillac STS?

  A: Start Thermostat Housing (LH2) replacement by draining the cooling system followed by Throttle Body and manifold absolute pressure (MAP) sensor removal. Disconnect both the hose and electrical connector from the evaporative emission (EVAP) canister purge solenoid valve. The use of clamping pressure allows extraction of the heater inlet hose, radiator inlet hose, heater outlet hose, bypass hose, and surge tank inlet hose from around the Thermostat Housing and thermostat unit. Follow this procedure to extract the Thermostat Housing: free the intake manifold duct clamp and unscrew bolts (1,2) that fasten the housing to the cylinder heads. Remove the old gaskets from the Thermostat Housing system and clean the outlet compartment fully after taking away parts such as the intake manifold inlet duct with clamp, surge tank inlet hose fitting, heater inlet hose fitting, and evap canister purge solenoid valve if a new component is required. Install all fixtures using the correct torque values: set the intake manifold inlet duct to 6 nm (53 inch lbs.), tighten the surge tank inlet hose fitting to 18 nm (13 ft. Lbs.) and the heater inlet hose to 20 nm (15 ft. Lbs.) while the evap canister purge solenoid valve bolt requires 12 nm (106 inch lbs.). The thermostat output bolts require new gaskets while one of them extends 10 mm beyond the others. Begin by securing the Thermostat Housing with bolts while tightening each one to 25 nm (18 ft. Lbs.). Afterwards, apply 6 nm (53 inch lbs.) of tightness to the intake manifold duct clamp. The hose connections to the thermostat and Thermostat Housing should be established first followed by reconnecting the evap canister purge solenoid valve hose and electrical connector. Install the MAP Sensor then the Throttle Body before filling the cooling system.