need help with over heating prob.

[buff531]

hey guys,
im posting this for a friend of mine. I have always came to you all for help when fixing my stang and figured you may be able to help on my friends car.

hes got a 96 pontiac sunfire and when he would drive around, occasionally it would overheat. i flushed the system and now the car overheats right away even higher than what it used to... everytime.

anyone know what would cause this?

any advise would greatly be appreciated. Thanks guys.

Adam:SNSign:

 

[bill302]

1 reason could be someone put stop leak in the system which was stopping up an internal leak and when you flushed it you cleaned out the stop leak creating a bigger internal leak....have you checked all other causes is the fan operating properly is the thermostat good ect...and has the system been loosing coolant meaning did coolant run low for no apparent reason and you had to replenish it...

 

[HISSIN50]

When does it overheat (while going slow or stopped, or while driving along at a good clip)? How hot is it getting (numerical value)?

Is fluid going into the overflow bottle when it gets hot?

More info will be needed. Good luck.

 

[buff531]

well i went to try and change the thermostat out but the bolts ended up stripping. i have to wait until monday or tuesday to get a tool to get them out.

as far as loosing coolant, no it never had that problem.

 

[HISSIN50]

Whoops, I thought the t-stat had been replaced already (I remove them to flush cooling systems). That is definately a place to start.

For stripped bolts, I've had good luck with the Bolt-outs from Sears (and they're open on the weekend if you wanna work on this).

Good luck.

 

[vristang]

How well did you purge the system of air?

It may be that simple?

 

[buff531]

When does it overheat (while going slow or stopped, or while driving along at a good clip)? How hot is it getting (numerical value)?

Is fluid going into the overflow bottle when it gets hot?

More info will be needed. Good luck.

i havent tried letting it run at idle but it starts overheating as i drive it. it gets up to yellow/ red mark before i shut her down.

yes fluid is going into the overflow bottle when it gets hot. The radiator cap is actually on the overflow bottle. and it seems as if it gets full when it over heats. when its cold theres some coolant in the bottle but when its over heating... the entire bottle is filled.

 

[buff531]

i purged it for air by releasing the pressure from the radiator cap...

how do you purge it for air?

 

[vristang]

After doing any work on the cooling system that causes a loss of coolant, you need to ensure that there are no small pockets of air left in the coolant passages. An air pocket will prevent coolant from flowing, and coolant temps will skyrocket.

After getting the system back together start the car and let it warm up at an idle. Do not install the radiator cap before starting the car. With the cap removed, any air that is in the system will be able to purge out the radiator filler neck.
Some people will recommend running the heater on high while doing this, but I am unsure how much it really helps. It certainly can't hurt.
You may see the coolant level drop as the air is purged, so keep some extra coolant/water near by to top things off.
Some people will use a jack to raise the front drivers side of the car, which helps the air purge from the rad.

Hope that works for you

jason

 

[HISSIN50]

I havent had to mess with Degas cooling system plumbing too much - not sure about the air purging. It sounds like Jason and others have you covered.

Good luck.

 

[buff531]

im purging the system now. car is at idle at operating temp. i saw the coolant level raise and spill out. looks like air is escaping. how long do i let it run for?

 

[buff531]

ok the car has been purging for over a half hour-hour now. i still have the low coolant light on.

the car doesnt seem to over heat but the temp gauge gets pretty dam close to the warning light.

any other ideas?

 

[HISSIN50]

Is it a Degas system?

Topping off the overflow might get the coolant light to go off.

Good luck.

 

[buff531]

what is a Degas system? sorry i dont know that term..

here is something else that may help you guys out. I let it idle for awhile with the radiator cap off... it didnt over heat. i then drove it around with the radiator cap off. temp rose just a hair but not into the danger zone... it was close but not in...

i let the car cool down and the resivoir tank was empty so i put some more coolant in there and put the cap on. drove it around and it overheated.

does that mean theres air still in there somewhere?

 

[buff531]

since i just got done driving it and it over heated... i let it cool down and the resivior is empty. On the resivioir itself, theres a mark that says Cold Level. Obviously meaning that is the level it should be when its cold.

i started the car again with the resivoir cap off, at the begining the resivoir was pretty much empty, i let it get to operating temp and there was a little bit of coolant in the resivoir. I sat in the car with the engine at about 2,000 RPM until i noticed the temp gauge to rise. At that point i went to look at the resivoir and it was almost completely filled. Since i wasnt pushing on the gas, the level in the resivoir started to descend. To me this sounds like a block somewhere... coolant is trying to flow but it cant so its coming back to the resivoir tank.

i didnt change the thermostat cause the bolts holding the caseing are stripped. however the upper radiator hose is really hot so this tells me that the thermostat is working. do you think this could be causing a blockage?