Purging Cooling System

[1996GT]

I just did the radiator flush/thermostat this weekend and i think theres air in the system. Does anyone know how to purge the cooling system. The needle will hit 3/4 and come back down to the middle. Im not sure if thats it but someone suggested purging. Thanks.

 

[JerZeyStangz]

When your trying to get the air bubbles out of the cooling system you have to make sure that the overflow is full so the air can rise to the top, and keep the car revved around 1500-2000rpm so the air can be forced out. If the needle is fluxing around like you said there still might be a little air trapped in the system.

 

[joekd]

Best way I have ever found to make sure you have no air in the cooling system

Pop one coolant temp sensor out of the intake. Top off the reservoir tank and cap it. Fill through the intake (where you removed the sensor) until it starts to come out. Unscrew the reservoir cap and you will see the coolant in the intake drop a little. Keep doing this until you cannot fill it anymore through the intake. Put the sensor back in and run the car. Usually I wait until the fan comes on then shut the car down. Wait for it to cool then pop the sensor back out and top off if needed.

 

[DropTopPony]

When your trying to get the air bubbles out of the cooling system you have to make sure that the overflow is full so the air can rise to the top, and keep the car revved around 1500-2000rpm so the air can be forced out. If the needle is fluxing around like you said there still might be a little air trapped in the system.

I do this and turn on the heater.

 

[1996GT]

For how long do i rev the engine? Until the fan comes on? Or do i just leave the top off and rev a little and let it idle until the fan comes on like joekd suggested.

 

[joekd]

I did mine twice and never once left idle, just dont see a need for it myself since the water pump circulates coolant at any RPM

Use the engine warmup time to clean up your tools, crack a beer and other such activity

 

[1996GT]

Cool. Im gonna try both methods and hopefully thats the problem. On the way home from work today, it was still climbing up to the L. But i notice its only on the freeway. In stop & go the needle will bounce around the M. Weird, oh well wish me luck!

 

[1996GT]

I finished with the purging. Hopefully i got it right. One thing i noticed though, is that the fan didnt come on until i turned the heater on. When is the fan supposed to come on? It was idling for a good 10 minutes. The needle was right in the middle but the fan didnt come on. Is this normal?

 

[KB98GT]

like everyone else said. let car idle with cap off. turn heater on high watch for bubbles once bubbles stop your good to go. ohh and add fluid as needed. to easy!

 

[1996GT]

I went ahead and purged the system like everyone suggested but it didnt work. I noticed the temperature only goes up when im on the freeway. As soon as i get off the freeway, the needle drops back down to right before the half way mark. Even in stop & go traffic. Is that normal?? I dont have any leaks or cracks that i know of. I even tried a bottle of water wetter, and changed out the thermostat twice. I dont get it? Anyway if you guys have any more suggestions id really appreciate it.

 

[Traidmarx]

i would suggest topping off the coolant..taking the radiator cap off..also jack the front of the car up because naturally as in all liquid bubbles will float to the top...so make the radiator cap the highest point...bubbles will naturally travel there. let the car run till it gets to normal operating temp..make sure its not bubbling..and seal it back up..you should be done.

 

[1996GT]

I will try that method also. I also noticed the fan doesnt come on until i turn the heater on. Also, am i supposed to see any movement in the radiator reservoir?

 

[vermilion]

remove reservoir cap. squeeze the upper and lower radiator hoses with car off. do this until you see the air in the reservoir stopping. add water if needed. run the car briefly. then do it again.

 

[1996GT]

Thanks. Does anyone know why the car runs cooler in stop & go traffic as opposed to the freeway where the needle goes all the way up to the L. Its never passed the L but im sure its not good for the car to run that hot, right?

 

[1996GT]

well i couldnt get this thing to cool down so i tok it to the local shop. They said it is the water pump since it only runs hot at higher speeds. Once im in stop & go traffic, it cools down. Go figure.......

 

[vermilion]

could have done it yourself in a couple of hours and saved precious $$$$