2001 3.8L V-6 Grand Prix GT overheating

**Kathy Nipper Smith** · 07-12-2012

First of all. I am a mom that is trying to get our Grand Prix up and running to par. I have this wonderful car that we've had for years. It's a 2001 Pontiac Grand Prix GT 3.8L V-6 with about 180,000 miles on it. Lately its been running very hot. Just sitting idle, she's running barely under the red. I've replaced the temp sensor, temp gauge as well as the Coolant sensor and its still running way to hot. The fan is kicking in, but not until its barely under the red mark. I know its full of coolant and there are no leaks anywhere in the entire system. The water pump isn't leaking or showing any signs of unusual noises.

Any clues as to what to look for or check next? Thanks for any helpful tips or suggestions!

**dsmuts** · 07-12-2012

Have you flushed the coolant system?

**ctracer** · 07-12-2012

it might be just a gunked up radiator, your car has quite a bit of miles on it. before you go checking into other big things, i would do a coolant system flush just to get all that old stuff outta there.

**Kathy Nipper Smith** · 07-12-2012

Had it flushed last year.

**dsmuts** · 07-12-2012

Did they put the green or orange coolant back in it and what did it have before?

**Kathy Nipper Smith** · 07-12-2012

Green before and green now.

**ItHurtz** · 07-12-2012

tstat

**dsmuts** · 07-12-2012

try using your garden hose and spray backwards through the rad. The fins could be gunked up with years of junk on them

**Kathy Nipper Smith** · 07-12-2012

WIll try that. Thanks!!!

**ItHurtz** · 07-12-2012

question is, does it run hot while driving or just at idle

**Kathy Nipper Smith** · 07-12-2012

It runs hot as well. About 235ish while she's running down the interstate. Higher sitting at stop lights or sitting idle...

**The Guz** · 07-12-2012

Originally Posted by ITHURTZ

tstat

You should also look into this as well.

**Fivefingerdeathpunch** · 07-12-2012

Did you happen to bleed the air out of the cooling system after you replace the temp sensor and others?

I just have a hunch that you just have alot of air in the cooling system and its causing it to run hot.

**Kathy Nipper Smith** · 07-12-2012

I did bleed the air out.

**wavedout33** · 07-12-2012

when's the last time the hoses were replaced? wondering if maybe the hoses are collapsing?

**Bessesen2** · 07-12-2012

damn grand prixs are always having problems....cant get rid of it though i love it too mch

**Kathy Nipper Smith** · 07-13-2012

I don't know that the hoses have ever been replaced. Unless they are collapsing while I'm driving (and can't see it) they are fine. Checked them while reving the engine and setting idle...

Isn't that right Bessesen2! Love our Grand Prix. Sexy car with muscle and dang good gas mileage! It's been a great car with very few problems. With as many miles as it has on it, I'd say we've definately gotten our money worth out of the old girl. I know she'll still be a good car if we can just figure out this overheating issue...

**BillBoost37** · 07-13-2012

if the hoses are collapsing under pressure, then you would need a radiator cap, which can also cause a car to run hot. Because then it's not under pressure etc.

**PurpleGuy** · 07-13-2012

Check the fins on the radiator. They could be bent up from rocks etc hitting them. Does it blow hot air? Could
jave a gunked up heater core.
I know you said there isn't any leaks but are you for sure the lower intake gaskets dont leak? Have the ever been replaced?