cooling system has me fustrated [Archive] - Forum


View Full Version : cooling system has me fustrated

08-18-2009, 09:30 AM
Hey all,

02 GAGT here,
Problem: overheating
Replaced: water pump, tstat, radiator, ALL gaskets from the head up, reservoir cap, and spark plugs (unrelated).

While over heating sometimes my heater is blowing hot air sometimes not, when it is blowing hot air the engines cools down a smidge, when it's not it doesn't.

when this started I had noticed a blanket of cotton covering the radiator(i own the worlds largest cottonwood tree), so i cleaned it which did not resolve my problem, I then replaced the water pump and tstat just because it was affordable and a common cause of problems which did not fix it. I took it to Lentz for a free diagnoses, they said that it was the head gasket (exhaust in my cooling system), so I replaced that which did need replacing.

Now i'm stumped, i've taken off all hoses and checked them, i've sprayed water using my garden hose in all the ports that deal with the coolant and everything appears to be working as intended.

I really need help with this.

I know i'm leaving out a lot of details, so please ask me anything, i'll checking this thread constantly.

Any help will be greatly appriciated


08-18-2009, 10:33 AM
ever try purging the cooling system of any trapted air? I beleive there is a bleeder screw by the front valve cover for this.

08-18-2009, 10:44 AM
ever try purging the cooling system of any trapted air? I beleive there is a bleeder screw by the front valve cover for this.

I've tried various methods for filling the cooling system, including using the bleeder valve. I've recently read on these forums to run the car with the heater/fan at max and just fill the reservoir until it's full.
I'm not saying that I don't have an air bubble because that would explain most of my issues, but i'm doing what I can to prevent that.

If someone has a way to fill it guaranteeing no air bubbles then I'm all ears.

Thanks for the response

08-19-2009, 09:20 PM
run the car with the coolant cap off and the heater on high defrost. fill the coolant to the fill line or so and let the car build temp. The air will find it's way out of the bottle. That is what I did the other day after replacing the w pump and I have no issues.

08-20-2009, 07:12 AM
i had the same problem. the way i fixed it was to fill the overflow to the full line, put the cap on and start it. wait fot it to get up to opperating temp. when it does, check for heat out of the vents inside the car. to get heat on mine i had to rev it up a bit. once you have good heat, turn it off immeadtly and let it cool COMPLETELY(4-6hrs). once cooled, refill your resivoir and you should be set. NOTE: if you hear air coming out when you go to fill it, let it cool a bit longer, though it may stilll happen. You may have to repeat the procedure to get all the air out.

also, you could still have a bad overflow cap. (i know you said you got a new one)

08-23-2009, 08:06 PM
fan workin? by itself no a/c on. radiator and heater core def not clogged?

08-25-2009, 12:41 AM
my car was doing the same, i used a hose to flush the heater core and it worked fine after that.

08-28-2009, 06:34 PM
You did not mention how the car overheat - was it overheat constantly after reaching operating temp. or it will overheat only when sit / idle? If only when sit, it could very well be your cooling fan is not running. How hot it get to - all the way to 260 or only goes to 220 ish?

If it goes all way to 260 (if kept on driving), the head gasket job might be defective - did they send the head to a machine shop to check for crack or warping? If not, you might still has a leak around the head.

From what you described, it definitely sounds there are air in the cooling system - and the most likely cause is a leaky head / HG. Does the coolant comes out of the overflow tube? Does the coolant level in the reservoir rise after driving?