I have an 06 Monte Carlo. Last spring had to install a new water pump. This winter when driving it blows hot air but when I come to a stop it blows cold air. Is this a low rad fluid situation or a thermostat situation. I took the cap off on the engine and tried to get some rad fluid out to test it but the 5 inch hose won't pick up any fluid with the engine cold. Should I add some more fluid?

If I have to change the thermostat, how much of a pain will it be.


I would really love some help on this.

sunnyvale311@yahoo.com

 

I would say there is a bubble in your coolant system, and or its too low. if you cant see the coolant its too low.. To fill my montes coolant properly you have to open the bleeder valves. while filling the system. Im not sure weather or not its the same for your year model, but on mine theres one bleeder above the water pump to bleed the radiator, then a second over by the throttle body for the heater core bleeding. both have to be done, in the correct order i think...

 

His unfortunately doesn't have bleeder valves, your thermostat could be shot, and it's a PITA on the 3.5L

 

I was afraid of that. Irregardless, your still way low on coolant if you cant get it to pickup any coolant with a 5 inch hose....

 

I've got an 07 and it is doing the same thing. I have only had it for a few months and at first the heater was super hot. After a few weeks of cold weather it started blowing cold unless i was accelerating. Glad to know I'm not the only one but the problem itself sucks.

 

I added two quarts of antifreeze and I am getting better results. Car would not warm up in town. Now car is warming up.... not calling the problem completely solved yet.

 

I admit, I don't know anything about the 3.5, but in basic coolant checks on any car, it's best to periodically check your radiator. If it's not filled with coolant add more. You are probably dealing with an air pocket.

If you are able to get consistant warmth from the blower (but you don't feel it's as warm as it should be), then it's probably a t-stat.

Also, watch you temp guage. It can give you some indication to what may be going on (such as if the temp guage reads real HOT, but the air coming from the blower is ambient temp, not warm at all, you probably have an air pocket still).

 

I believe in order to bleed your car you have to drive it, so add the coolant, drive around and then check the coolant again when it cools off and see if you have to add more.

Repeat about 3 times, or until your car is full after the drive