Where is the heat going ?

Hello !

I have 1996 Cavalier and can't figure out where the heat is going ? The engine temp guage barely comes off the cold, and yes I did check to make sure it is working.

My first though was that I was loosing my heat through the cabin heater, the air mix jammed and I was running cold air through cabin heat exchanger and that was enough to keep my heat down. I checked that out by clamping off the heater hose but there was no significant change in the engine temp.

I previously replaced the thermostat 2 times but the engine still didn't warm up. I clamped off the rad hose and engine still didn't heat up.

Any ideas where the heat is going ?

Take Care
Roy

Did you find an answer for your heat problem? We are having the same problem on our 1999 cavalier. We are going to change the thermostat agen but I do not think that is the problem. We also noticed that the compartment temature goes down when you sit at a stop light. I was thinking it might be the water pump but if that were the case you would think it would overheat. If you find an answer let us know.

Hi !

I've spent most of the morning working on this, I believe that it is the thermostat. I have a couple here that I have tried as well, the one that I removed because of an overheating issue, when your compare it to the new ones that I have the spring on the back is much smaller diameter. I believe that the lighter spring is allowing some bi pass and as the outside air temperature drops even a small by-pass brings the temperature down.

I'll keep you posted

Take Care
Roy

Ok, here is the deal. I spent most of the day working on this problem. A few hours research and a few hours in the shop and a few hours trying to find the thermostat that I need. (This is Canada and most of the parts places close at 12 on Saturday) There are 2 thermostats and the difference wouldn't be noticeable unless you knew to look for the different spring diameters. Apparently the water pressure is high enough that you need the heavier spring in the Cavalier, and by trial and error, I have to agree. I finally found the thermostat with the heavier spring and all is fine again. The NAP part that I used was THM531090.

I also drilled a 1/16 hole in the flange for equalization and bleeding the air through.

Take Care
Roy