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caintmakit
10-19-2005, 07:31 PM
I’m looking for some advice on a cooling problem I have been fighting with. For whatever reason, my cooling system pukes around a gallon or so of fluid during warm up.

I have a 69 Camaro with a 350, a Weiand high volume aluminum water pump, and a 3 core copper radiator with a 13 psi cap. Every time I drive the car, it pushes a bunch of water out the overflow when it warms up. Once the thermostat opens, the car seems to run fine and doesn’t use any more water.

This weekend, I started the car without the radiator cap on to see what was going on. Long before the T-stat opened, I could see water vapor coming off the heater hose going into the intake. The upper radiator hose was cold, and the temp gauge had not begun to move yet. However, the level in the radiator kept rising and it started pushing water out. Once the T-stat did open, the level in the radiator dropped to about half full.

Does anybody have any idea why the car would be doing this? I changed the cap out for a new 16 psi unit and it’s still doing it. It does not appear that the lower radiator hose is being sucked closed. Could it be something with the heater core? I’m pretty much lost as to what is going on.

Any advise you guys have would be appreciated.
Thanks
Marty

porschev8
10-19-2005, 10:41 PM
The heater lines bypass the thermostat. That's why you see coolant flowing through the heater lines before the Tstat opens.
The reason why the coolant level rises inside the radiator before the t-stat opens is because the heater return line connects back to the low pressure side of the system. Squeeze the upper hose the next time you see the level rise like that, I bet you'll find that it's almost empty.
It sounds like you're just chasing a giant air pocket around.

It's perfectly normal for the system to push coolant out the overflow every time the system warms up, It's supposed to do that. You need to install a coolant recovery tank so when the system cools down, it pulls coolant back into the system rather than pulling air.

Are you sure that the system is puking an entire gallon of coolant?

caintmakit
10-20-2005, 06:34 PM
Thanks for the reply.
I understand that it should push some coolant out during warm up, but it never did before, and it's pushing what I would consider an unusual amount of coolant out.

Not sure exactly how much it's pushing out, but the radiator overflowed for quite some time. Once the T-stat did open, the level in the radiator dropped to about half full. I would say it took about at least 3/4 of a gallon to fill the radiator back up again.

So if it is an air pocket, what's the best way of getting rid of it? I've been driving the car off and on, so it's got a few miles and heat cycles on it. I would have thought it would have worked its self out by now.

Any other ideas to try? Should I try closing off the heater hoses or removing the T-stat and see what that does?

thanks
Marty