Hey guys, you will be my last help before I take the car do the dealer... I live in Ohio, and the weather's been pretty nice in the past week or so, therefore I never needed heat in the car anymore. Should I say... I actually have used just the blower on 65 degrees. Today was different, it was pretty chilly outside, and when I got in the car, I turned the heat up on 85 degrees on step one, and realized that when I stopped at a light or when the car is parked (but on), the AC will not blow heat, it would automatically change to blowing in cold air (even though the engine was fully heated up). Not AC, but just cold air. Any ideas why this would happen?

 

Thermostat working ok?

 

that is the calssic sign of a clogged/restricted heater core. when you drive the water pump is turning faster pushing the coolant through. how does th motors temp act? easiest fix is to buy some prestone super radiator cleaner (not the flush) and give it a thorough cleaning. hardest fix is to remove heatr core and clean/replace it.

 

what does the temp gauge say? if it drops too, then thermostat. if not, most likely the heater core is clogged. I assume the coolant level is ok?

out of curiosity, what is the car's cooling system service history? any previous flushes? what type of coolant did you use? did you use tap water?

 

Temperature gauge is fine, so I suppose the thermostat is ok too. Car leaks coolant somewhere right in front of the right front wheel, I haven't gotten a chance to take a look at it yet, but there is plenty of coolant in there (I have to keep refilling because of leaking). Do you guys have any ideas what would be leaking there? I haven't gotten a chance to research yet, so maybe I should do that first. As for the history of the cooling system, I haven't done anything to it, since it's been working just fine up until now, and I don't know what the previous owner has done to it. I have never used tap water either.

I suppose I should clean / replace the heater core as 2da_mizzax said.

 

What about the module that selects hot versus cold? Mine doesn't do anything when I slide the temp over to hot. Whatever the servo or motor that moves the door etc is not working. The climate control seems to function fine except for that and the position of the vents which may be by the same motor for all I know. Any ideas?

 

Bump! Katrina needs a/c for the summer! Currently stuck on mildly cool, lol. Is it a servo or a motor or a magic wand? Thanks