2003 Pontiac Grand Prix GTP...Overheating. Temp gauge rises 3/4 of the way while idling. While I'm driving it normally sits at 210.. Before i have any issues it would sit at the first bold line past 160. I flushed & bled the radiator. replaced temp sensor & thermostat.. Still having the issues. Buuuut, when it says its close to 260, my heater stilll isnt hot. Would like some help please!!!!

15

Asked by Sep 29, 2014 at 06:22 PM about the 2003 Pontiac Grand Prix GTP

Question type: Maintenance & Repair

11 Answers

5,055

Could be several things. Since you already replaced the thermostat and temp sensor, I would look at whether your fan (assuming it is electric) is operating. Without a working coolant fan, the radiator has a hard time keeping up with the heat load.

1 of 1 people found this helpful.
1,175

You still have air in the cooling system. You;ll have to keep bleeding the air off until you get nothing but coolant. Once you have ALL the air out the engine temperature will go back to normal and you will get heat from your heater when you need it. It's difficult to get the air out of the system but with continued bleeding you will succeed. GOOD LUCK WITH IT !!

1 of 1 people found this helpful.

If it has the 3400

Sorry hit the wrong button if it has the 3400 motor you have a warped head I see the same problem in that motor all the time

1,175

It would not matter what engine it is, as long as it is a liquid cooled engine the symptoms that DaniEllie described are indicative of air in the cooling system. Get the air out, the steam pockets will not be able to form, and the coolant will be free to flow to the heater .

1 of 1 people found this helpful.
1,175

A 2003 GTP has the supercharged 3.8.

15

We bled it until nothing but coolant was coming out.. It is the 3.8. We've been having bad issues since my dad soaked my engine.. The problem seems to be fixed now and its running like new again. Thank you for all the answers!

1 of 1 people found this helpful.
1,175

I'm glad it worked out for you, good luck with it.

1 of 1 people found this helpful.

I had the same problem with my 2003 pontaic grand prix 3100 the car was getting hot. we changed the water pump, the thermostat, the radiator radiator holes line both. And the temperature coolant sensor. Still getting hot , we bleed the Lind for air. So finally we decided to put your old temperature sensor back in just to see what will happen and everything happened. The car didn't get hot we drove the car so it turned out the coolant temperature sensor we bought was defected it was the problem too the whole car. The car not getting hot any more. Thank you everyone for all your subjection.

1,175

Don't try to reinvent the wheel, their problem was solved at least 2 years ago!!!!!

1,175

Have fun with y our car, my 2000 GTP has 140,000 miles on it and it still gets 21 mpg in hilly country driving and 30+ mpg on the highway. BTW this thing is still as hot as a $2.00 pistol!! They are great cars!!!

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