Why is my car overheating AND heat/defrosters don't get hot?

We had really cold weather the past couple days, and my car wouldn't start (1991 Firebird). It took a few tries to get it started, but eventually it did. I let it warm up awhile, and then drove it around a little. I noticed that the coolant temperature was about 230 degrees after that (it's usually around 200-210 when it's warmed up).

After I shut it off, I checked the coolant, and it was low. So I added some. Then, the next day, I noticed a green puddle (the coolant) on the passenger side floor. This time, when I drove it, the temp reached about 240, almost into the red zone (250-260 F). I didn't think overfilling the coolant would really damage the car since it just empties into the street.

The whole time though, since I saw it overheating, the heat and defrosters were COLD--even though the engine was overheating! The windows were very foggy and did not clear except a little bit, and the air coming out of the vents was cold.

This only started last night. Before that, everything was ok. What is wrong?
 

Jake1

Active member
Could be your heater control valve.
When they go bad, they usually stay open or closed.
When that happens, coolant leaks onto your floor.
They cannot be refurbished and the only solution is a new one.
Good luck
 

AnthonyB

Member
Well if the coolant leaked onto the passenger side floor inside than the heater core is leaking, since it is what supplies the heat the coolant just leaks out when it passes through it. Replace the heater core.
 
the Little green puddle is your heater-core leaking. when a heater core leaks it will not give out heat of defrost your windows. And when it leaks enough your engine will overheat because the heater core gets its source from your radiator. So replace the heater core and you wil fix two problems at once. Auto-Zone may have it with a life time warranty.
 

sparks

Member
The thermostat is probably at fault and is stuck in the closed position not allowing water to circulate through the heater cores, or engine.
 

fugenduben

New member
If there is coolent on pass front floor your heater core is leaking! Also it sounds like your thermo stat is stuck open or your water pump is not working! Poor cirulation !
 
Top