06' Grand Prix heat not hot...

[tdub36tjt]

My Grand Prix's heat is warm but not hot. I am thinking it might be the thermostat, but I am confused on how to read the temperature gauge on the car. It doesn't display the actual temperature so I am not sure where the 200 degree mark is?? Mine is running slightly above the first line above the bottom. Also when in heavy stop and go traffic will run slightly hotter...

Also, I checked the heater core hoses and the inlet is slightly hotter than the outlet but both feel pretty warm to the touch....

[jmoore4294]

Warming up is normal in stop and go traffic. Your thermostat may be going bad, but you could also be low on coolant or have an air bubble trapped in the cooling system. Have you had your cooling system serviced lately or checked your coolant level to see if it's low?

[tdub36tjt]

Checked the coolant it's not low. As for needing to be bled I haven't had any service done other than when I hit a deer not sure if thats when I started having trouble or not. Or even if they touched the radiator, but I guess I can try bleeding it. Where is the bleeding valve located? Do you know?

[jmoore4294]

Follow the upper radiator hose to the thermostat housing. There is a bleeder valve on top of the thermostat housing.

[tdub36tjt]

Cool thanks. I'll give that a try.

[tdub36tjt]

Ok, I tried that and it didn't help any. Next step thermostat?? Or should I just flush the heater core even though both hoses seem to be hot.

[tdub36tjt]

The red line is where my temperature is running. It seems low, but I am unsure. Is it?? If so, I would have to think its the thermostat being stuck open??

[Filion]

i have the same problem, i get some heat but not much, and my gauge wont move except if im stuck in traffic.

[tdub36tjt]

I went ahead and changed the thermostat and it is running hotter and the heat is a lot better. But still no heat in idle and it is running hotter in idle and is smoking a little???....I bled the coolant system again after the thermostat install...

[matt1long]

I had this problem im my 04 gt and just fixed it..... i spent like 200 dollars at a shop to do everything....My car was running at just about the 1/4 white mark....heater was fine but the car was not at normal running temp, ( gave me a check engine light which fails instantly on PA inspection) I simply had the coolant sensor, and thermostat replaced and bled the coolant and waaa laaa....all is well heats to just slightly about the middle white mark and stays there

[tdub36tjt]

I bled it again and I think that might have fixed it. The heat is still kinda cold when in idle but other than that seems to be working pretty good. I might try to flush the heater core on my next day off to see if that makes it even better.

[Nuzzget]

Sorry if this sounds dumb but in my 06 grand prix it seems i always have to put that button with the arrow inside the car (forgot what its called) on.

[tdub36tjt]

Ok so this hasn't solved my issue. Seemed to work temporarily but I am back in the same boat. So I bought a flush kit and am going to flush it when I get a nice enough day to do it. The flush kit instructs to install the t in the inlet hose from the engine wall. Which one is the inlet the top hose or the bottom hose??

[Gorecki]

I had this problem im my 04 gt and just fixed it..... i spent like 200 dollars at a shop to do everything....My car was running at just about the 1/4 white mark....heater was fine but the car was not at normal running temp, ( gave me a check engine light which fails instantly on PA inspection) I simply had the coolant sensor, and thermostat replaced and bled the coolant and waaa laaa....all is well heats to just slightly about the middle white mark and stays there

Dude, it's quite likely you got railroaded, what you described is nothing more than bad thermostat stuck open and the threw 'low coolant temp' code which sets of the check engine light. Coolant sensors rarely go bad, should have been a $10 fix.

[Gorecki]

Ok so this hasn't solved my issue. Seemed to work temporarily but I am back in the same boat. So I bought a flush kit and am going to flush it when I get a nice enough day to do it. The flush kit instructs to install the t in the inlet hose from the engine wall. Which one is the inlet the top hose or the bottom hose??

You can most certainly try the flush, it could be the heater core isn't flowing well, but it's sounding like the heater core regardless.

In the top and out the bottom on the other side I believe.

[asmith533]

Ok. I know this is an old post but I am having a similar problem with my heater. The car is heating up between the 1/4 and 1/2 point on the temp guage. We have replaced the thermostat, the water pump, and flushed the coolant system. Any suggestions???