OEM 2007 Chevrolet Cobalt Thermostat Housing

2007 Chevrolet Cobalt Thermostat Housing Parts and Q&A

• Q: How to replace the engine coolant thermostat housing (RPO L61) on 2007 Chevrolet Cobalt?

  A: To perform the replacement of the engine coolant Thermostat housing (RPO L61), first take off the intake manifold cover and drain the cooling system, allow the use of the drain found at the lower part of the Water Pump for the engine block coolant drainage. Once this is done, close the drain bolt and bring down the vehicle. For automatic transaxle models, do not disconnect the engine coolant temperature (ECT) sensor electrical connector; for manual transaxle models do the same thing. Knock off the heasng Oxygen Sensor heater (HO2S) electrical connector clip from the Thermostat housing and if necessary, remove the ect sensor. Position the radiator outlet hose clamp used to be in a new location and remove the radiator outlet hose from the Thermostat cover. Next, dismount the Exhaust Heat Shield studs and the Exhaust Heat Shield. Reposition the heater inlet and outlet hose clamps at Thermostat housing pipes, then remove heater inlet and outlet hoses(1, 2) lift and prop up the vehicle, then just pull the Thermostat housing bolts and twist the water transfer pipe as you pull it away from the Water Pump. Take off the Thermostat, as well as the pipe transferring water to it (on the Thermostat housing) if needed and throw away the o-ring seals if any. Unscrew the Thermostat cover bolts and cover, and clean all debris and thread sealant from the ect sensor and bolt holes if reusing the housing. Install: put a new Thermostat cover o-ring seal into the recess groove, install the Thermostat if necessary, tighten the Thermostat cover bolts to 10 n.m (89 lb in). Mount a new Thermostat housing to engine gasket on to the Thermostat housing, ensure that the water feed pipe seals are lightly lubricated with coolant before putting in new o-ring seals onto water feed pipe; ensure that these seals are lubricated with only coolant. Put the water feed pipe in the Thermostat housing noting the locator tab, strapping it to the Water Pump and using care to seat the o-ring seal. Mount the Thermostat housing on the engine and tighten it to 10 n.m (89 lb in) housing bolts. Lower the vehicle and hook the heater inlet hose (1) and outlet hose (2) up to the Thermostat housing pipes, fasten the hose clamps. Re install the Exhaust Heat Shield and tighten studs to 22 n.m (16 lb. Ft.). Secure the radiator outlet hose onto the Thermostat cover and place the radiator outlet hose clamp. If replacing the old sensor, apply a coat of sealant on the threads before installing the ect sensor and securing it to 20 n.m (15 lb ft). Attach both manual and automatic transaxle models ect sensor electrical connector and then attach the ho2s electrical connector plug to the Thermostat housing. Level the vehicle as you fill the cooling system, make sure that drain valves on the radiator and Water Pump are closed, lower the vehicle, fill the cooling system, and lastly, attach the intake manifold cover.