Heater blowing cold air

[lawadm1]

2005 Grand Prix GTP.

The other day I was checking the fluid levels, and I noticed that the coolant reservoir was almost completely empty when the engine was cold. So I added some DEX 50/50 coolant to the reservoir (about 3/4 full).

Now the heater blows out cold air, even after driving for 20 minutes. Is it possible that when I added the coolant to the reservoir, that it got air in the coolant lines because it was nearly empty before?

Thanks,
Jeff

 

[rynoman03]

Also possible that you have a bad thermostat that is stuck open. Just throwing that out there. Let the car sit overnight then check the level the radiator. Pop the cap open and take a look. If its not to the top add some.

 

[nos4blood70]

Second the bad thermostat. Before you replace it, fill and burp the cooling system.

 

[lawadm1]

Thanks for the replies. I was actually looking up the best way to burp the cooling system for this car, but the best I could so was a youtube video on a 2004 Impala 3.8 Series II. Would this be close enough? Here's the link: Chevy Impala 3800 series II - How to bleeding engine cooling system.4/4 (2004 yr) - YouTube

I'm no where near being a mechanic, so if it's recommended that I take it in to someone, then that's what I'll do.

 

[lawadm1]

A friend and I attempted to burp the coolant lines tonight. While cold, the radiator was already full, so with the cap off I let the car run for about 8 minutes with no signs of air bubbles. I put the cap back on the radiator, started the engine again, and the heater still blows cold air.

Both hoses to the firewall are warm to touch, so does that mean the culprit could be the stuck open thermostat? Or could it be a heater core issue?

 

[Utter99]

Might be clogged if you've ever used bars leak or a previous owner you could pull the hoses off and flush it out . I know you said both hoses are warm so persay it should work. Make sure you bleed the system well by the needle on top of the thermostat but might as well change the thermostat then since collant will be lost

 

[Fivefingerdeathpunch]

Bleed it with the bleed screw/bolt on the thermostat housing.

 

[lawadm1]

@fivefinger Are you saying that I should try bleeding at the bleed screw first before changing the T-stat? Or get the new T-stat and don't forget to bleed?

 

[Fivefingerdeathpunch]

New themostat then bleed with bleeder screw on theremostat hosuing.

Wouldnt be a bad idea to flush the coolant too, if you havent ever done that.

 

[lawadm1]

So we are going to change out the t-stat. And we're going to flush the system as well.

I'm going to go with the 180 degree t-stat. Do I need the O-ring and gasket for the water outlet? And Do I need to lubricate the o-ring and gasket before installing it? What lubricant is recommended?