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Help!! 2004 Overheating


garittle
09-09-2010, 10:36 AM
I have a 2004 Grand Prix GTP that will only go about a 1/2 mile before the temp guage goes to the edge of the red (sometimes to the middle of the red) stays there for a minute or two and then goes down to the middle and then goes backup. This process happens the whole time the vehicle is running. There are no leaks and I have flushed the cooling system, changed the thermostat, cap and have bled the air out. Also the car idles rough. These problems started after I blew a heater hose fitting and the vehicle went into Overheating Protection Mode. Does anyone have any ideas? Any and all help is greatly appreciated.

Thanks!

dewaynep
09-09-2010, 10:52 AM
It sounds like you either have air in the system still (not fully bled out) or there is more air being introduced by a blown head gasket. You can go to AZ and rent (free) a cooling system pressure tester to see if it leaks down at all. If it does, you've got a leak somewhere, if not, then you haven't bled all of the air out.

garittle
09-09-2010, 03:04 PM
Ok, I will go get the pressure tester and let you know the results.
Thanks for your help!

danielsatur
09-09-2010, 08:53 PM
5-years it's time for coolant flush and a thermostat!

BNaylor
09-10-2010, 10:53 AM
5-years it's time for coolant flush and a thermostat!

I believe the op stated that was done. Post# 1.
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doctorhrdware
09-10-2010, 09:22 PM
Could it be that the LIM gasket failed, and that is causing the ruff idle?

garittle
09-11-2010, 11:18 AM
The only coolant system pressure tester I could rent was from oreilleys and it does not have an attachment that fits my threaded radiator cap opening. Is there any other way to test for an internal leak?

Thanks in advance for any and all help!

tblake
09-11-2010, 01:07 PM
Start it up, get it to operating temp, and look.

Check places like near the injectors (LIM Gaskets), waterpump weep hole, and 90 degree plastic elbows on the passenger side of the motor.

danielsatur
09-11-2010, 01:59 PM
Are the electric cooling fans working proper?

BNaylor
09-11-2010, 03:15 PM
The only coolant system pressure tester I could rent was from oreilleys and it does not have an attachment that fits my threaded radiator cap opening.

A special adapter is required to connect a vacuum gauge and pump to run a cooling system leak down test. GM J 42401, Radiator Cap/Surge Tank Test Adapter.

Other visual things you can do is check for coolant in the engine crankcase. Pull the dipstick or drain out some old oil. Oil or other combustion byproducts in the cooling system. Inspect coolant at the radiator fill neck and overflow reservoir. Pull the spark plugs and do a read. Engine compression test which should detect a blown headgasket.

Also, GM recommends that you replace the oil and filter after a overheated protection mode event and actual engine overheating. For those unaware in overheated protection mode the PCM module alternates firing of the cylinders so you can get to a safe place but this reduces engine performance or may feel like a misfire condition.

garittle
09-11-2010, 07:22 PM
Found the leak(s)!! They are coming from the intake manifold in multiple spots. To double check I sprayed carb fluid around the intake and the idle went up on the car. I also double checked the oil and it is not milky and there is no scent of anti-freeze in the oil.
Are there any tests I can do to triple-check that this is my problem. Also how big of a job is it to replace the intake manifold gasket on this GTP for a novice do-it-yourselfer?

BNaylor
09-11-2010, 08:38 PM
What part? Where the supercharger mounts to the lower intake manifold or the lower intake manifold to the cylinders heads? The supercharger is also the upper intake manifold.

garittle
09-11-2010, 09:12 PM
Lower intake to cylinder heads

danielsatur
09-12-2010, 12:08 PM
Do a smoke test!
Google ''Youtube Auto vacuum smoke test''

garittle
09-22-2010, 05:32 PM
The only leak I could find was the leak in the LIM gasket. I have fixed it and there are no more leaks. I have one remaining problem as to the overheating and the problem is that after you have been driving for say 20 min the car will start to get hot and stay hot, it seems that all of the water in the radiator is going into the coolant reservoir and staying there. Water pump going out?
Any and all help has been and is greatly appreciated.

Thanks!

tblake
09-22-2010, 08:14 PM
The only leak I could find was the leak in the LIM gasket. I have fixed it and there are no more leaks. I have one remaining problem as to the overheating and the problem is that after you have been driving for say 20 min the car will start to get hot and stay hot, it seems that all of the water in the radiator is going into the coolant reservoir and staying there. Water pump going out?
Any and all help has been and is greatly appreciated.

Thanks!

Uh oh, That scares me.

When you replaced the LIM gaskets, did you replace the t-stat as preventative maintenance?

I hate to say this, but when I hear about coolant getting pushed into the resivore, in the back of my mine, the first thing I think is a blown head gasket. There are a few things you can do first to make sure. Change the t-stat if you haven't, and swap out the radiator cap with a known good one or replacement.

When your car is dead cold, and you start it, grab your upper radiator hose, does it get hard immediatly? Or stay soft until it reaches operating temperature?

garittle
09-22-2010, 10:10 PM
I replaced the thermostat and radiator cap 2 weeks before I changed the LIM gaskets, but I will change them again. I will let you know tomorrow on the hose.

Thanks for your help!

garittle
09-23-2010, 09:09 AM
The radiator hose stayed soft until the engine got to operating temp. While checking the hose I did find another leak, bummer, it is leaking from the thermostat housing. I will replace the gasket when I replace the thermostat later today.

garittle
09-24-2010, 08:42 AM
I changed out the thermostat (fixed the leak) and the radiator cap and I still get all of the water from the radiator in the coolant reservoir. :frown:

tblake
09-24-2010, 08:59 AM
Does it fill the resivore, or overflow? And when the car cools off, does it suck back into the radiator?

Can you hear or see air bubbles coming out of the overflow resivore when the car is running?

garittle
09-24-2010, 10:41 AM
No it does not fill it. No it does not suck it back to the radiator when cooling off. Yes I see the water bubbling when the car is running and when I shut it off there are bubbles for a few minutes.

dewaynep
09-24-2010, 10:58 AM
Wow, sure sounds like a bad head gasket...

tblake
09-24-2010, 02:53 PM
It does sound like a leaky head gasket, but you could also have a big air pocket in your cooling system from replacing your LIM gaskets. Did you bleed the system?

Sometimes I have even had to lift on the passenger side front to get the radiator fil higher than the rest of the motor. Then open the bleeder screws and fill till coolant starts coming out the bleeders. Close them, put the cap on, then start and let it run to operating temp. Open and close the bleeders untill no air is heard bubbling out. Periodically check the coolant level in the radiator.

garittle
09-24-2010, 04:08 PM
I have bled the system, I filled the radiator with the bleeder screw open until fluid comes out of it, start the car and turn on the heater on high, let it warm up until I get hot air from the heater open the bleeder screw - fluid, close the bleeder, wait a couple of minutes, open bleeder-fluid, close the bleeder, wait a couple of more minutes open the bleeder-fluid. After a couple of more minutes the car gets hot and I shut it off. Should I keep bleeding even when the car gets hot? What did you mean about lifting the passenger side?

tblake
09-24-2010, 06:24 PM
I usually have to open the bleeder a few times after ther car gets hot to purge the air out.

Sometimes on some of them GM FWD cars, they wont bleed at all. The impala's with 3400sfi motors come to mind. I had one 03 impala 3400 I replaced the waterpump on, It had a big gulp of air in it and would not bleed out no matter what I did. I ended up jacking up the passenger side front of the car about a foot or so off the ground. This gets the radiator fill neck up above the rest of the motor and sometimes will make it easier to bleed.

BNaylor
09-25-2010, 07:42 AM
Run a compression test. It sure sounds like a blown head gasket to me too.

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