2 yrs.,ago, i had to replace the water pump for my 2006 pontiac grand prix as well as the thermostat, that was in october, when winter came in late january of the following years, no heat. verything

Asked by May 22, 2017 at 03:25 PM about the 2006 Pontiac Grand Prix Base

Question type: Maintenance & Repair

the heat has not worked in two years. in winter if the outside temp  is above 35,
the heat works just fine, I even have to lower it. if the outside temp falls below
32 or 33, no heat at all.  the compressor works just fine,  air conditioner no
problems. I don't detect any coolant leaks very rarely need to replenish the
coolant. replaced the thermostat twice, no change.
any suggestion as to what can cause this malfunction in winter.
Thanks;
Harold G.

4 Answers

2,175

I believe u are looking in the right area. How many miles on your car? When u can tell me the color of the exhaust when idling? Is it white? Have you replaced the radiator cap in a while as well? What does your temperature gauge read along the way?

2,175

Also check...if both hose to the heater core are hot and the heater core is not leaking there is probably nothing wrong with the heater core . I would check to see if the diverter door is working . it usually works on vacuum and changes the direction of the air flow from vent to heat or ac when called for

2,175

I had a similar issue to this on my 2006 Grand Prix. After painstakingly removing the glove box to look at the blend door actuator, I found it to be working normally. In hindsight, I didn't need to do all of that work, because I could actually hear the actuator working when I changed the temp control knob. You should be able to hear it run and bottom out when you are all the way cold or all the way hot. This shows that both the actuator is working and the blend door is not jammed. I suggest the next step will be inspecting the heater control valve, and I am confident that this will fix it.

2,175

Lastly, this is a very common problem in Pontiacs. I have changed the water pump, thermostat, and radiator. Most likely what happen is someone mixed 2 different kinds of coolant and it created a orange clay that clogs the radiator and the heater core. If u have this orange clay in your car, u will go threw hell to get this fixed. First off u need a new radiator, cause there is no way u r going to get it clean, I tried. When u install the radiator do not connect it to your cooling system yet. Next, flush the inside of the engine with hot water, when flushing, take a break and let hot water sit in the engine to help break down the orange clay, and keep flushing out. This will take awhile. Then splice the heater core lines, and get connectors to put the heater core back together. Now I got muriatic acid and I poured about 3/4 of a cup down in the heater core and had pressured hot water ready to shoot threw the line after u pour the acid in. Do not let that acid sit in there, if u leave the acid in too long it will ruin the heater core. After u flush the acid out, have a air hose to shoot threw the line and shoot all the water out. Keep putting hot water in the heater core and blowing out. I shoot the water in the inlet and after I did that, I switch to the outlet. I did this about 30 times. 15 for the inlet and 15 for the outlet. This should fix your heater problem. That orange Dex cool is junk

Your Answer

Grand Prix

Looking for a Used Grand Prix in your area?

CarGurus has 2,659 nationwide Grand Prix listings starting at $1,750.

ZIP:

Pontiac Grand Prix Experts

  • #1
    Js08016
    Reputation
    4,470
  • #2
    Tom Demyan
    Reputation
    3,110
  • #3
    munron
    Reputation
    2,500
View All

Related Models For Sale

Used Chevrolet Impala
570 Great Deals out of 34,332 listings starting at $900
Used Dodge Charger
444 Great Deals out of 33,205 listings starting at $1,999
Used Pontiac Bonneville
488 listings starting at $1,799
Used Chevrolet Monte Carlo
10 Great Deals out of 1,249 listings starting at $1,500
Used Ford Mustang
573 Great Deals out of 38,832 listings starting at $1,895
Used Pontiac Grand Am
1,072 listings starting at $1,800
Used Pontiac G6
40 Great Deals out of 3,851 listings starting at $1,200
Used Pontiac GTO
6 Great Deals out of 442 listings starting at $4,995
Used Chevrolet Malibu
1,050 Great Deals out of 61,498 listings starting at $880
Used Chrysler 300
327 Great Deals out of 19,363 listings starting at $900
Used Jeep Grand Cherokee
1,029 Great Deals out of 71,559 listings starting at $1,195

Used Cars For Sale

2008 Pontiac Grand Prix Base For Sale
9 Great Deals out of 391 listings starting at $1,750

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.