Today my car developed a very strange reaction to turning on the heater: the coolant temperature increases to 205 at idle with heater on, 190 with heater off. How is this possible?

 

probably because racecar

 

I don't even want to use my heat due to the blower motor rattling and chirping. :@

 

Lol

 

Mine's always done something like this too, and I've wondered the same thing. Turn the heat on, and coolant temp goes up a bit. Turn it completely off, and coolant temp goes back down a bit, and it does it every time too. It seems reverse intuitive, so there's got to be something going on that I'm not thinking about. I asked some Cobalt friends and their's all do the same thing too.

 

is the heat control on defrost when you turn the heat of? where the heat comes out up by the wind sheild and at your feet. try turning it to blow out the face vents and see if it changes. i forget what part runs differently but you can hear it in the idle of the car. when your in your car idleing after its up to running temp,turn the heat on level 1 or 2 and then turn the heat control from your face to the feet/defrost.

 

same thing happens to mine sometimes. the way i fix it is by going faster o.O . like 5mph faster though, more air flow =]

 

Ecotecs just do that. If you leave it on high for a while the temp will come down. Ive had mine go down to 165 with the heat on at idle.

 

yea mines gone up to 215 in the middle of winter before with the heat on wtf lol

 

Soofisahab,

If you wanted for me to check with our Technical Assistance Center on this, please contact me via private message with the last 8 digits of your VIN and your inquiry.

Sarah, GM Customer Service

 

mines more a spitting noise

I crank that bitch all the way up so i don't get pissed off

 

defrost runs on your AC system so when your vehicle's defrost is activated the AC motor is turning which causes the extra load, which changes your idle

 

ahh thats what it was.


i had a squeeky blower motor and i got pissed and took it to the dealer and they replaced it under warranty

 

They only lubed mine when i still had warranty.

 

Wasn't on defrost, but went ahead and cycled the vent control and the temperature didn't get above 200 at idle. Maybe a.c. was on after all. If it reoccurs, then the heater core has to be restricting flow somehow.

 

the cobalts and G5's vent selector isn't aligned properly, if it's set the floor (straight up and down) its actually activating the defrost, if you put it one click to the left its not.

 

I have noticed this too. Pain in the ass. Really just a cheap design. But it's ok.

 

ya i tested it with 5 brand new ones and 5 used ones ranging from differen't years. they all do it. its annoying.

 

Mine makes a "chirping" noise in the morning when the outside temp is around 40... Doesn't do it as much when it's 60+ outside. Anything I can do to fix it? Should I take it in under GMPP ($100 deductible though) or is there an easy fix for that?

 

chances are the chirping is your blower motor. should be covered under warranty

 

serega12,

If you do decide to work with your dealership, please keep me posted as I'm available to do any follow-up. I can be reached either via private message or email (include your name, the last 8 of your VIN, and the name of your dealer).

Sarah, GM Customer Service