Geo Tracker Overheats, Blows hot air on any temp setting


#1

'92 Tracker. Overheats in stop and go, holds okay temperature when moving. The thing that really puzzles me is that the heater constantly blows hot air, even with the temp control turned all the way to cold. The vehicle does not have AC.

What are some of the things I can check/replace before I have to give over and take it to a mechanic? Hoses, radiator cap… Thermostat I don’t think I’d want to attempt since I remember a friend having one helluva time getting the replacement to seal. Any feedback is appreciated! Oh, and I can tell you that my roommate had the Tracker for 2 or 3 years before passing it along to a friend in need, and she had not done any radiator maintenance that I can recall. Thanks!


#2

Sounds like two different problems.

The first problem may be the blower motor or temp sensor switch.

The second problem is the control valve that regulates the flow of water to the heater core. Now some cars don’t have this…hot water is always flowing to the heater core. Instead the temp is controled by doors that direct the air.


#3

Is the radiator cooling fan working? It should cycle on and off as needed to draw air through the radiator. If it’s not working the engine will heat up in traffic.

The interior heater is a separate problem. I’d check to see if the air temperature blend door is functioning properly. If the door is not moving, it can send air through the heater core all the time, which is exactly what you’ve got.


#4

Can you tell me where the air temperature blend door is located? Is this under the hood? Thanks