Intermittent Heat Issue?

[552Drive]

2006 Grand Prix is having intermittent issues with heat:

- antifreeze is at correct level
- car is at normal running temp
- blower motor seems to be working fine - low - medium - high
- air is blowing "cold" but no heat coming out

Any thoughts or known issues here?

[Scottydoggs]

flush the heater core. sounds like you got air trapped in it.

[Fivefingerdeathpunch]

Dat heater core be plugged.

[552Drive]

Thanks for the responses. How do I flush the heater core on this car - I assume it's up under the dash like most?

[Scottydoggs]

two hoses from behind the alt to the fire wall. take both off th ealt bracket, run a garden hose to one hose till water comes out, then do the other hose to back flush it.

try to keep both hose as full of water as you can when you put them back on the alt bracket.

take hoses off engine cold. but while its warmed up, both hoses should be hot to the touch. if one is ice cold and one hot, the core has air in it. if one is hot the other luke warm, its got air. both should be hot.

[552Drive]

Thanks again! Will give it a try. Think I already know the answer, but how painful is it to R&R the heater core in this car?

[Scottydoggs]

thats no fun, not your issue unless its clogged up solid.

touching the hoses is the place to start. these cores get air bound all on their own, the core sits lower then the engine pretty much. its dead center the dash on the hump in the floor somewhat.

[552Drive]

ok will give it a try! Thanks for the advice. Last heater core I R&R'd was on a 1974 AMC Matador my gramps had given me for free...and it was a beyotch to do...

[Scottydoggs]

im willing to bet if you thought that car sucked, you'll want to kill yourself during a w body core swap lol

best core i ever changed was my 77 caddy, it was under the wiper cowl, took all of 4 bolts and maybe 15 minutes to change standing at the fender lol aka cake job.

i thought my core was leaking in my regal, so i took it out and found it to be ok, so i put it back in, took 4 hours. same set up as a gp.