How do you change thermostat on 1995 4.9 straight 6 motor?

Answer 1

# After the engine cools, drain about 4L of coolant from the radiator into a container. Store this container where no pets can reach it (it is very dangerous to pets). # Find the thermostat. This part is very easy. Starting at the radiator in the front of the vehicle, find the large rubber hose (approx. 1 1/2" to 2" in diameter) that is attached somewhere near the top of the radiator. Follow this hose toward the the engine. At the end of the hose you will see a metal housing that usually looks like a small dome (sometimes they are shaped like a cylinder with the top side flat). This dome (aka the Thermostat Housing) will be attached to the engine by two bolts. Remove those two bolts and pull the thermostat housing away from the engine (note: make sure your engine has had time to cool down because when you remove the thermostat housing, coolant may spill out and could cause injury). It might be easier to remove the upper radiator hose to get it out of the way. # Beneath the thermostat housing lies the thermostat. The thermostat should just be resting there and come right out when you pull on it. Now take a clean cloth and wipe off the surface around where the thermostat was sitting and the underside of the thermostat housing (if the old gasket is really gunked on there you made need to take a razor blade or special scraping tool and carefully scape the old gasket off, be sure not to scratch the metal surfaces to much). # When you purchase your new thermostat make sure to also get a new gasket and some RTV (silicone) sealant. Place a small amount of the RTV around the thermostat hole on the engine (this doesn't take much, just a 1/16" inch film on the surface where the gasket lies), place the new thermostat in the hole, with the spring side sitting in the engine (the pointy end faces you), and place the gasket against the engine, with the gasket holes lining up with the bolt holes in the engine. Finally just bolt the thermostat housing back on to the engine and you are ready to go. # Very important note: make sure the new thermostat is within the groove in the housing. If not, when you tighten the bolts, the housing will break and you will have to replace it - probably special order that will take a couple of days. You could even use a couple of dabs of glue. # Replace the coolant you drained earlier - reuse the old stuff. # NOTE: It is also a good idea to run your vehicle for a little while afterwards until it gets up to temp. then allow it to cool down and check the coolant level in your radiator.