2000 Celica gts Mind warping issue - Toyota Nation Forum : Toyota Car and Truck Forums

Crishquawg · 11-14-2007, 02:30 PM

Hi, I severely need some help with my 2ooo gts.
WhenI'm driving @ normal operating temperture with my heater on full blast my heater only blows cold air then my car will say that it's overheating and if you wait a second, while still driving the heater puts out just a little hot air and the the car automatically goes back to normal operating temperture. It does this over and over again. Sometimes when I'm on the freeway though, the heater blows hot and the car stays @ normal Temp. It'salways an issue in stop and go and in areas wherte the speed limit is like 50 mph and below.
WHAT DOES THIS POSSIBLY MEAN??? SOMEBODY, ANYBODY< PLEASE HELP!

wiccanferret · 11-14-2007, 02:43 PM

Sounds like your thermostat is sticking closed. Replace your thermostat and see if the problem goes away. And don't drive it when "says it's overheating" because odds are pretty good that it is.

Crishquawg · 11-14-2007, 03:16 PM

So, The thermastat has something to do with me not getting hot air through my A.C. when the heater is on? other than the overheating.

Boxedin · 11-14-2007, 04:35 PM

It is also concievable that your coolant temperature sensor is bad, or shorting out. It could be reading hot, or normal and yet your coolant is actually cold, not allowing the heater to produce hot air. Although if it is the thermostat, which it may be, flush the anti-freeze thoroughly. Secondly the antifreeze could be experiencing electrolisys (sp?)
causing false readings in the sensors and contributing to the heating problem, you can make sure this is not a problem also by flushing the antifreeze. Let me know if I can help further

wiccanferret · 11-14-2007, 05:03 PM

Quote:

Originally Posted by Crishquawg

So, The thermastat has something to do with me not getting hot air through my A.C. when the heater is on? other than the overheating.

Yes. When the engine reaches a certain temp, the stat opens letting the coolant flow into the block and the heater core. The heater core gets its heat from hot coolant. If the stat isn't opening, there's no coolant hitting the engine (overheat) or the heater core (no heater).

Crishquawg · 11-15-2007, 12:56 PM

Thank all of you so much for your quick and helpful responses!
I should have mentioned previously that I did check the thermostat all ready. It seemed to be working fine. I also replaced the Temp Sensor. It was a little coroded. neither of these two thing aleviated the problem. Although after i got off line yesterday I decided to jack my front end up and remove my radiator resevoir cap to let the car run for a while incase there was air trapped in the coolant system. Sure enough she started burping. After that I drove it to the mechanic shop across town. It didn't over heat once on the way there so I turned around and came back home. It's been fine ever since. Damn Air!!!!
Again Thank all of you.
Chris

wiccanferret · 11-15-2007, 04:37 PM

Wow, I didn't know Toyotas could be that sensitive about it. Watch out, that air got in there somehow which means you have a leak I would bet...