Pontiac 10190925 Thermostat, Engine Coolant

To remove the thermostat, start by draining about 1 gallon of coolant from the radiator until the level is below the thermostat housing. Then, remove the air intake duct and disconnect the radiator hose from the thermostat cover. Next, remove the bolts and lift off the cover, tapping it with a soft-face hammer if necessary to break the gasket seal. Take note of how the thermostat is installed, and then remove it. Make sure to use a replacement thermostat with the correct opening temperature. If a gasket was used, use a scraper or putty knife to remove any old gasket material and sealant from the mating surfaces. To install the new thermostat, ensure the correct end faces out, with the spring directed toward the engine. Use a new rubber gasket or apply a bead of RTV to the groove in the coolant outlet sealing surface if no gasket was used. Carefully position the cover and tighten the bolts to the specified torque, being careful not to over-tighten and risk cracking or distorting the cover. Reattach the radiator hose and tighten the clamp, and consider checking and replacing hoses and clamps at this time. Finally, refill the system, run the engine, and carefully check for any leaks.

Don't drive without a thermostat; it impacts emissions and fuel economy. Before replacing the thermostat, inspect coolant level, drivebelt tension, and gauge operation. A slow-warming engine indicates an open thermostat, while an overly hot engine with a cool upper radiator hose suggests a closed one. Overheating can cause damage like leaking head gaskets and warped cylinder heads. To replace the thermostat, drain some coolant from the radiator until below the thermostat housing. Disconnect the upper radiator hose, remove the housing cover, and note the thermostat's position. Clean off old gasket remnants, then clean the surfaces with acetone. Apply ATV sealant, position the new thermostat, and attach a new gasket. Secure the cover, reattach the hose, and refill the coolant system. After running the engine, check for leaks.

Disconnect the negative battery terminal and remove the air cleaner on V6 and V8 engines, labeling all detached hoses. Drain the cooling system below the thermostat level and disconnect the upper radiator hose. Remove the thermostat housing bolts and separate the housing from the engine, possibly removing the alternator bracket first. If a TVS switch is present, disconnect vacuum hoses and unscrew the switch. Remove the thermostat, noting its orientation. Clean old gasket residue from the thermostat housing and engine sealing surface. Apply a 1/8-inch bead of RTV sealant to the engine's sealing surface, place the thermostat, and position the housing with sealant and a new gasket. Tighten the bolts to the specified torque. Reinstall any removed parts, reconnect the upper radiator hose, and reinstall the air cleaner.

After installing the new thermostat, reattach the radiator hose to the cover fitting and tighten the hose clamp.

Begin by draining about three quarts of coolant from the radiator until the level is below the thermostat housing.

Refill the system, run the engine, and carefully check for any leaks.

Remove the thermostat from the housing.

Start by draining about 1 gallon of coolant from the radiator until the level is below the thermostat housing.

Start by draining about 1 gallon of coolant from the radiator until the level is below the thermostat housing.