Make sure there's enough coolant, the drivebelt is tight, and the temperature gauge or light work before you think the thermostat caused cooling trouble. When your engine warms up slowly according to both heater strength and temperature gauge readings, a damaged thermostat is likely keeping the water door open. Simply replace it to get back to normal. A malfunctioning thermostat could be the problem if your engine heats up and the upper radiator hose doesn't feel warm - you'll need to replace the thermostat then. Connecting from the upper radiator hose reveals moving liquid, working thermostat. First turn off our battery, take out the air tube connecting the throttle body and air filter, then drain the vehicle's radiator while saving any recent or in quality coolant. Find the thermostat housing at the front of the intake manifold by tracing the upper radiator hose from the engine. To separate the hose from the coupling, loosen the bolt that secures it. Push the hose free from the fitting by twisting it withpliers that adjust. When the outer part of the big fitting fails, you must replace the thermostat housing cover. Loosen the bolts, and take off the housing cover. Gently hit the cover with a special hammer in case it is stuck. Then get ready for some fluid to escape when you take it apart. When you remove the thermostat, make note of how it was originally placed, and turn it in different directions as needed to get it out. Take out dirt from both the housing and cover, and scrape off material with a gasket tool. Clean both surfaces with acetone or lacquer thinner. Put the sealing ring on the thermostat as shown, then place the new thermostat in the housing with the connecting piece toward the outlet cover and close the vent valve before screwing on the cover. Fit the housing cover over the assembly and bolt it down tightly, connect the hose back to the fitting, and secure the hose clamp. Fill up the cooling system, attach the cleaned air cleaner duct, start the car, let it warm up to normal running temperature, look for any leaks, and check the thermostat works correctly.
