Coolant issue - ZR-1 Net Registry Forums

secondchance · 06-10-2013

I have a strange situation. As the coolant get hot (normal operating temp) it overflows into the overflow tank at front right of the car - so far so good. As she cools, expansion tank does not such the coolant back from the overflow. After the car has cooled, when I open the radiator cap (17 lbs rated factory cap) I hear pressure being relieved and bubbles going into the overflow tank. Not only that but also I find the radiator expansion tank about a gallon short from being full. It almost looks like expansion goes to overflow tank but the cooling system cannot replenish as the system cools down.
Any thoughts?

Is it normal for the expansion tank to be about a gallon short when the cooling system is cool ?

06-10-2013	#1
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,726	Coolant issue I have a strange situation. As the coolant get hot (normal operating temp) it overflows into the overflow tank at front right of the car - so far so good. As she cools, expansion tank does not such the coolant back from the overflow. After the car has cooled, when I open the radiator cap (17 lbs rated factory cap) I hear pressure being relieved and bubbles going into the overflow tank. Not only that but also I find the radiator expansion tank about a gallon short from being full. It almost looks like expansion goes to overflow tank but the cooling system cannot replenish as the system cools down. Any thoughts? Is it normal for the expansion tank to be about a gallon short when the cooling system is cool ? Last edited by secondchance; 06-10-2013 at 12:36 AM.