2006 Grand Prix Overheating and Low Cabin Heat?

officerdave
90

Asked by officerdave Sep 20, 2013 at 08:41 PM about the 2006 Pontiac Grand Prix GT

Question type: Maintenance & Repair

I have a 2006 Grand Prix Gt 3.8 Supercharged. I was gettin glow cabin heat so I flushed out the rad and heater core added new Dexcool mixed 50/50 and the engine started overheating and still low cabin heat. I have changed the thrmostat and still the same low cabin heat unless the climate control is at max and still running very hot almost in the red.

38 Answers

dandyoun
58,225

Was it overheating before you flushed it? If not did you properly burp the air out of the system after you flushed it?

2 out of 2 people think this is helpful.
officerdave
90

N ot wasn't overheating before and I burped it several times and bleed it off threough the valve on the top of the water neck.

2 out of 2 people think this is helpful.
dandyoun
58,225

Oh ok. Sure sounds like it might still have some air trapped in it.

1 out of 1 people think this is helpful.
judge_roy
Not Active

Look under hood for evidence of a prior overheat...someone fixed the leak (probably with a buck knife cutting the bulbous portion off) and refilled with tap water or hose water causing corrosion and you engine getting buggered up and the radiator gettin' choked...use a 14 dollar thermal spot gun to measure the hot spots...then replace the radiator...I'm sorry its a pain in the ass on your model but must be done if choked with rust~...you could try flushing if you could recover into five gallon buckets for environmentally disposal recycling...even if laden with rust, can pull the ethylene glycol out of there and make money off of that~ New radiator....coolant flush and fresh 195 thermostat...cross your fingers that coolant gets to critical areas after that....sell it to a kid when that doesn't work~

officerdave
90

I have tried burping it many times and ran it with the bleeder valve open as well a few times and still no change

1 out of 1 people think this is helpful.
judge_roy
Not Active

you could check the engine temperature sensor to make sure the fans will come on when it comes up to operating temp...a fuse or relay might be causing the overheat~

1 out of 1 people think this is helpful.
officerdave
90

I have owned the car since new and have taken very very good care of it. Other than thjis problem the car is in fantastic condition not a mark on it

1 out of 1 people think this is helpful.
dandyoun
58,225

And overflow resivoir is filled to proper level?

1 out of 1 people think this is helpful.
officerdave
90

Corrrect

1 out of 1 people think this is helpful.
dandyoun
58,225

And the cap is in good shape? A bad cap can cause one to overheat.

1 out of 1 people think this is helpful.
dandyoun
58,225

Not to change subject but with the cabin heat. Does the air blow good and strong or feel weaker than it use to?

1 out of 1 people think this is helpful.
officerdave
90

Air is very strong

1 out of 1 people think this is helpful.
judge_roy
Not Active

dip tube on reservoir cap in place?

1 out of 1 people think this is helpful.
judge_roy
Not Active

coolant flow is good...measure with a fourteen dollar lazer thermal gun...the fans come on at 195...where's the problem?...choked radiator...measure the hot spots with a lazer gun~

dandyoun
58,225

Are your radiator fans coming on when it starts to overheat?

1 out of 1 people think this is helpful.
dandyoun
58,225

Oh and with bleeder valve open is coolant coming out the bleeder?

Best Answer
officerdave
90

yes there is coolant coming out of the bleeder and the fans stay on

1 out of 1 people think this is helpful.
judge_roy
Not Active

sure the radiator isn't doing it's job~

officerdave
90

the engine runs very hot in traffic almost in the red the heater fan blows hard but only have cabin heat if I turn the climate control to 30 or 32 which is max other than that I have cool air and a hot running engine. I have no idea wha tis causing this

judge_roy
Not Active

obviously the thermostat is not opening~ make sure that yours was not installed upside down~

1 out of 1 people think this is helpful.
officerdave
90

I have checked it and it is in correctly it is a T stat direct from GM

1 out of 1 people think this is helpful.
judge_roy
Not Active

for funzies, you could run without it...and see if you're getting heat...else the heater core might be plugged?~

dandyoun
58,225

Have you ever put anything like stop leak in it?

judge_roy
Not Active

if feeling particularily vicious could connect the end of the heaterbox hose to a garden hose and capture the other side in five gallon buckets...this would blast out any corrosion and assure good flow through the heater core~...be sure to stop up the other side with a plastic bag and rubber band~

1 out of 1 people think this is helpful.
judge_roy
Not Active

dan-d's on the job~

1 out of 1 people think this is helpful.
officerdave
90

No I have never touched the rad before. I have flushed it out using the cleaner and now it overheats. And still very low cabin heat unless the climate control is turn to max

1 out of 1 people think this is helpful.
DavidH25
Not Active

There is a vacuum operated valve to shut flow to core on/off. Maybe stuck? Vacuum hose off?

3 out of 3 people think this is helpful.
DavidH25
Not Active

And that vacuum leak, IF it is, can cause a lean fuel trim and heat up and engine...? Guessing.

1 out of 1 people think this is helpful.
judge_roy
Not Active

...it's the cleaner and subequent failure the cause for concern here...am suspicious of Techron(tm) effect on fuel pressure regulators....did they ever do a check-see to see if there is significant deterioration of the diaphragm materials used?

1 out of 1 people think this is helpful.
DavidH25
Not Active

Naw the ECU would be able to correct the fuel/air trim if it's just a 1/4" hose leak

1 out of 1 people think this is helpful.
DavidH25
Not Active

You mean in Chevron gas?

1 out of 1 people think this is helpful.
dandyoun
58,225

Sounds like davidh25 might have this one figured out.

judge_roy
Not Active

additive designed to "CLEAN YOUR FUEL" often cleans the parts that are needed like the diaphragms that come in contact with it and hyper-sensitive gasoline seals~

judge_roy
Not Active

--- "flushed it out using the cleaner and now it overheats" has got me on my hind legs...trying to wrap my head around just how this may have gone awry~? `

1 out of 1 people think this is helpful.
judge_roy
Not Active

"cleaner" turns the boulders into dust?...something is like trying to recite the constitution with a mouthful of saltines~

DavidH25
Not Active

Shell and Exxon/Mobil have detergents...that is why I always pay a bit more for Shell. One station. They sell a LOT and it's always fresh, and often a police car there filling up, the City cars (all four of them) and County both...a dozen or so deputies cars for the surrounding countryside

1 out of 1 people think this is helpful.
judge_roy
Not Active

...yeah, officerdave---was there an increase in idle speed when the heat quit working? change the butyl rubber hoses (chewing gum with coal tar added) with silicone that will never fail or leak~

1 out of 1 people think this is helpful.
judge_roy
Not Active

a spool...one at a time for every single vacuum connection under the hood may prove beneficial as the butyl rubber ones WILL crack and leak without you recognising it~

1 out of 1 people think this is helpful.

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