I have a 95 Cherokee and it has recently started overheating. Just replaced the water pump in May and I just replaced the thermostat today. Started the Jeep, drove up the driveway (which required 4H) and it overheated as soon as I hit the road, about an eighth mile. I don't know what to do. Not very experienced with motors but I don't don't trust any one around here to work on my car for me. Any one have any advice?

 

Did you change the thermostat because it had been overheating, or did it only start to overheat after you changed the thermostat?

 

Did this Jeep have some sitting time where it wasn't driven for a long time? It sounds like your radiator or perhaps your block may be stopped up, not allowing coolant to circulate.

Does the aux cooling fan come on before the Jeep gets really hot? If not, it may not be detecting high coolant temp if coolant isn't circulating through the block & heating up.

When it gets hot, is the radiator also screaming hot, or just the engine itself? No coolant flow means the engine will get scorching hot while the radiator remains relatively cool.

If the cooling system is full of coolant /water / some liquid, and the drive belt is turning the water pump, (a new water pump at that), and the engine is still getting hot, the coolant must not be making the trip into & out of the engine.

 

Just to be certain, can you clarify on "overheating"? Some people hitting 210*F is overheating and spend tons of money trying to "fix it", but that's normal operating temp.

 

Usually takes about 3 heat/cold cycles to remove all the air out of the system. Make sure the reservoir is full enough as the coolant system will suck coolant out of the reservoir while it is cooling to replace the air. When it is completely cooled, add a 50/50 mix to the radiator at the cap to help remove air as well.

Like the others have said, check to make sure the coolant is flowing. If the upper radiator hose is hot and the lower hose is cold then something is wrong with the flow. Always change the radiator cap anytime you change the coolant or thermostat (should be rated at 16 psi).

 

That short distance should not have brought the engine to temp that fast. Your temperature gauge is fed by a sending unit at the back of the head and is separate from the sensor on the tstat housing that the computer uses. A pocket of hot air sitting at the back of the engine would read a lot hotter than the coolant around it.