Engine is running hot almost in red zone. I beleive it is the thermostat. Is that a good place to start?
I would start with the the radiator fan. Is it kicking on? With engine over heat it should be running hard.. (Dont poke fingers in there, might start any time) Try turn on heat to defrost and open front windows to dump heat, this should kick on the AC and 2nd fan and cool it off some, (as a quick temp fix to prevent boil over)
If fans do not run, check fan motor, disconnect fan harness and jump 12 volts to it. If it runs its good. Then there is a fuse and a relay in the elec box under the hood. check the cover for a guide or the owners manual. There is also an engine temp sensor, this may be attached to the thermostat cover. Unplug the wire and jump across the connectors with hot engine. If fan kicks on, the switch is bad.
If Fans are running, then consider thermostat. Will need replacing.
To replace thermostat follow this..
1.Buy a new thermostat, gasket and gasket sealant for your particular make, year and model car,at your local auto parts store.
2.With a COLD engine, open the radiator cap, but if its still warm, place a thick rag over the cap on the radiator and slowly turn it while listening for the pressure to be released. When it stops remove the cap completely.
3.Locate the thermostat by finding the two-inch thick black hose coming out of the top of the radiator. The hose will end somewhere on the top of the engine and it will be clamped onto the thermostat cover. The cover will have two bolts on each side.
4.Remove the hose by using the screwdriver or pliers to pull off the clamp. Some auto manufacturers use stainless steel clamps with a screw and some use a clip clamp. Twist the hose to loosen it from the thermostat cover. Use a spray lubricant if the hose is difficult to loosen. Be aware that a considerable amount of coolant will pour out of the hose when you take it off.
5.Loosen the two bolts on each side of the thermostat cover with an appropriate-sized ratchet socket or open-ended wrench. Lift the cover off and remove the thermostat.
6.Use a putty knife or scraper to remove the old gasket from the thermostat cover and cover base. Use a fine emery cloth to sand away any remaining traces of the gasket. Make sure the cover and cover base are smooth and clean or the cover will leak.
7.Drop the new thermostat with the spring mechanism down into the engine thermostat opening. Notice there is a narrow recessed area where the lip of the thermostat fits.
8.Spread the gasket sealant on the gasket side that makes contact with the engine. Place the gasket on the engine, making sure the bolt holes line up. Spread the gasket sealant on the edge of the thermostat cover also and replace the thermostat cover and screw the bolts in place.
9.Replace the radiator hose.
10.Wait for the gasket sealant to cure before starting the engine. Read the directions on the sealant package to determine how long the sealant needs to dry.
11.When dry, start the engine with radiator cap off and run it until it reaches the engine's normal operating temperature. Fill the coolant level to replace what is needed. Replace the rad cap. Check the thermostat cover and hose to make sure there are no leaks.
Aug 26, 2011 |
1993 Chevrolet Lumina