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Forum namePerformance/Engine
Topic subjectCoolant not returning from overflow tank?
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=114061
114061, Coolant not returning from overflow tank?
Posted by Agas, Oct-19-08 11:38 AM
so my car started overheating yet again today, and I looked at the overflow tank and it is completely full to the top now and hasnt returned to the radiator like it should I dont know why it wouldnt and I'm getting pretty close to just trading in the car
114062, RE: Coolant not returning from overflow tank?
Posted by 96TurboGS, Oct-20-08 03:44 AM
Don’t give up on the eclipse it’s a solid car, things tend to get old on it. Did you get all the air out of the system?? Pressure release caps are the shit. (IMO) Next would be the cheap things first like buying a new thermostat/overflow hose, if that doesn’t work go on about flushing the radiator and heater core. Make sure you have coolant in the upper radiator hose and the thermostat is opening at the correct temp before buying another one.
114063, RE: Coolant not returning from overflow tank?
Posted by dsmtuner1, Oct-20-08 06:46 AM
The coolant wont enter the system if its not flowing and not pressurized. Change your thermostat its probably not opening and its super cheap.
114064, RE: Coolant not returning from overflow tank? THE ANSWER
Posted by Star Turbo Talon, Oct-21-08 03:39 PM
Originally posted by 96TurboGS
Don’t give up on the eclipse it’s a solid car, things tend to get old on it. Did you get all the air out of the system?? Pressure release caps are the shit. (IMO) Next would be the cheap things first like buying a new thermostat/overflow hose, if that doesn’t work go on about flushing the radiator and heater core. Make sure you have coolant in the upper radiator hose and the thermostat is opening at the correct temp before buying another one.


Do you even understand how the recovery system works? Your just full of wrong advise.

Agas: the overflow system works simply. As coolant temp rises the coolant expands causing pressure to rise. As pressure rises in the cooling system towards 15~16psi the radiator cap spring will collapse allowing coolant to flow past the seal into the overflow bottle. Now as the coolant cools, the coolant contracts and pressure drops. the coolant system will now begin to form a vaccum. Look closely at your radiator cap, you will see the seal has a center section that appears it can open allowing coolant to flow past it. As a vacuum is created this center section opens downward allowing the vacuum to "pull" coolant from the over flow bottle. THIS IS WHY DINO TELLS YOU TO REPLACE THE CAP, IT COMMONLY FAILS.

Lets go farther shall we! What to we need in order for the coolant to get pulled out of the overflow bottle? A hose from the water neck correct? Well you have that! Next we need that same hose to be able to suck coolant out of the bottle, since we have a overflow bottle with a cap then the hose from the water neck must connect to the cap. the other side of the cap must go to another hose that is submerged in the coolant of the overflow bottle right? What is there is a crack in the hose or the cap right above the level of the coolant?

Ever went to use a straw with a hole in it and you couldnt draw pop out of your cup? Coolant overflow bottle is the same thing.

So what should you do? Take the cap off your overflow bottle and make sure the hose is still attached to it, check for cracks in the cap. If you feel bold, empty the over flow bottle out and rinse it with water. Fill with water and put the cap and hose back together. now take the hose that goes to the water neck and try to suck the water out of the bottle. If water comes out then the bottle assy is fine.

Your cap is the problem. If thats the case, the seal that seals the cap to the outer lip of the water neck is whats bad.

Relax, simple issue.
Terry
114065, RE: Coolant not returning from overflow tank? THE ANSWER
Posted by Agas, Oct-22-08 03:23 AM
Originally posted by Star Turbo Talon
Originally posted by 96TurboGS Don’t give up on the eclipse it’s a solid car, things tend to get old on it. Did you get all the air out of the system?? Pressure release caps are the shit. (IMO) Next would be the cheap things first like buying a new thermostat/overflow hose, if that doesn’t work go on about flushing the radiator and heater core. Make sure you have coolant in the upper radiator hose and the thermostat is opening at the correct temp before buying another one.
Do you even understand how the recovery system works? Your just full of wrong advise. Agas: the overflow system works simply. As coolant temp rises the coolant expands causing pressure to rise. As pressure rises in the cooling system towards 15~16psi the radiator cap spring will collapse allowing coolant to flow past the seal into the overflow bottle. Now as the coolant cools, the coolant contracts and pressure drops. the coolant system will now begin to form a vaccum. Look closely at your radiator cap, you will see the seal has a center section that appears it can open allowing coolant to flow past it. As a vacuum is created this center section opens downward allowing the vacuum to "pull" coolant from the over flow bottle. THIS IS WHY DINO TELLS YOU TO REPLACE THE CAP, IT COMMONLY FAILS. Lets go farther shall we! What to we need in order for the coolant to get pulled out of the overflow bottle? A hose from the water neck correct? Well you have that! Next we need that same hose to be able to suck coolant out of the bottle, since we have a overflow bottle with a cap then the hose from the water neck must connect to the cap. the other side of the cap must go to another hose that is submerged in the coolant of the overflow bottle right? What is there is a crack in the hose or the cap right above the level of the coolant? Ever went to use a straw with a hole in it and you couldnt draw pop out of your cup? Coolant overflow bottle is the same thing. So what should you do? Take the cap off your overflow bottle and make sure the hose is still attached to it, check for cracks in the cap. If you feel bold, empty the over flow bottle out and rinse it with water. Fill with water and put the cap and hose back together. now take the hose that goes to the water neck and try to suck the water out of the bottle. If water comes out then the bottle assy is fine. Your cap is the problem. If thats the case, the seal that seals the cap to the outer lip of the water neck is whats bad. Relax, simple issue. Terry


Love the way you explain things :cheers I'll try that
114066, RE: Coolant not returning from overflow tank?
Posted by DarkOne, Oct-21-08 04:41 AM
Replace your filler cap.
114067, RE: Coolant not returning from overflow tank?
Posted by DR1665, Oct-21-08 08:50 AM
Originally posted by DarkOne
Replace your filler cap.


Agreed.
114068, RE: Coolant not returning from overflow tank?
Posted by Agas, Oct-25-08 03:48 PM
ok replaced the cap and the thermostat today...will test later