Another Cooling question

[jcslocum]

Originally Posted by pilut2

In summary my questions are:

1) Is it normal for the coolant to go from min to way over max in the overflow tank when car it at operating temp?
2) Is it normal that the pressure relief valve is in the open position when hot?

Thanks!

To just stick to answering these 2 questions, yes, the coolant level will go up and down, the more air in the system the bigger the variance.

Yup, the little valve with the wire on top is allowing circulation when hot to move air from the system to the tank. If you park the car on a decent slope, nose down with the wire bail lifted to open the valve and let it idle, the air should migrate to the tank over time. If you can shut her down and leave it that way overnight, you should work the air out of the kinks and pockets.

A consistent burping of coolant can indicate a head gasket or other issues. Check the oil for water mix and you can have the air in the coolant system measured for combustion gasses.

Good luck!!

[pilut2]

Update: I can not hold vacuum in the tank it seems to be sucking around the pressure relief valve. A visual inspection of the tank doesn't reveal any cracks or leaks. The trunk has always been dry. When hot, the tank is above the full mark and coolant occasionally drains out of the black hose ahead and above the right rear wheel. If I blow into the tank it will not hold pressure, i can hear air leaking out- again it seems to be leaking through the pressure relief valve. Is it possible my valve is shot? The car has about 40,000 miles on it

[JFP in PA]

Originally Posted by pilut2

Update: I can not hold vacuum in the tank it seems to be sucking around the pressure relief valve. A visual inspection of the tank doesn't reveal any cracks or leaks. The trunk has always been dry. When hot, the tank is above the full mark and coolant occasionally drains out of the black hose ahead and above the right rear wheel. If I blow into the tank it will not hold pressure, i can hear air leaking out- again it seems to be leaking through the pressure relief valve. Is it possible my valve is shot? The car has about 40,000 miles on it

Your own tests say it is shot...............................

[pilut2]

Originally Posted by JFP in PA

Your own tests say it is shot...............................

Should I replace the whole valve or try the o-rings first?

[JFP in PA]

Originally Posted by pilut2

Should I replace the whole valve or try the o-rings first?

Depends upon how cheap you are and how much you like taking things apart multiple times before you solve the problem. Replacing the unit with a factory part (not an aftermarket version) gives you a new everything.