GM 22538325 Thermostat Assembly, Engine Coolant

It is not possible to test whether the thermostat works by opening the bonnet of the vehicle. Mostly, if you suspect that the thermostat is faulty, it is more cost effective to purchase a new one as they are not very expensive. To check remove first of all the thermostat. Look for excessive corrosion or damage on this device. Replace with a new one should either condition occur. Then put it in water 25 degrees hotter than that stamped on it. Since most Chevrolet V8 and V6 engines have thermostat at 195 degrees, the temperature of water will be just about 220 degrees Fahrenheit. In this water that must be well stirred, then submerged, its valve should open entirely. Remove it by using a piece of bent wire and then put it in water which is 10 degrees less than the figure indicated on its body. In most cases cooler water temperature should read about 185 degrees Farenheit. At this temperature, fully close thy valve on thy thermostat. Reinstall if satisfactory or buy another like-temped one for the purpose of installing.

A thermostatic element inside a housing on the engine actuates the thermostat, which is a restriction valve. It opens and closes to regulate coolant flow at predetermined temperatures, thereby enabling either engine warm-up or cooling. Disconnect the negative battery cable and remove the air cleaner so you can get at the thermostat with ease. Find a suitable container and drain the coolant into it. Remove the thermostat housing bolts and disconnect upper radiator hose from it. At this point, lift up the housing hence exposing the thermostat while considering where it was located previously for later replacement. Clean both surfaces of gaskets on housing and engine body. Insert RTV or equivalent sealer and put the thermostat onto its space properly. With new gasket, fit housing on with correct tightening of bolts. If necessary, re-attach alternator brace and TVS switch plus vacuum hoses as well. Make sure that upper radiator hose is securely attached. Reconnect negative battery cable then use right coolant mixture to fill radiator. Start engine; if necessary pour more coolant into system hereafter. Finally put back radiator cap matching arrows on it with overflow hose.

Engine coolant flow is controlled by the thermostat. In order to take it off, turn off the negative battery terminal and remove the air filter. Coolant should be drained and then upper radiator hose disconnected. The thermostat housing bolts can now be removed as well as the housing from the engine. Remember where the thermostat is located before removing it. It's important to clean gasket surfaces and apply sealing compound before installing new thermostat. After that, reassemble the housing, connect radiator hose and fill in coolant. Start the engine and add more coolant if necessary. Finally, put on the radiator cap.

The thermostat should be installed with the wax pellet facing downward.

To test the thermostat, first remove it. Inspect the thermostat for excessive corrosion or damage. Replace the thermostat with a new one if either of these conditions is found.

When submerged in hot water, the valve of the thermostat should be fully open.

After lifting the thermostat housing from the engine, the thermostat will be visible and can be removed from the engine.