Why is my Overflow tank blowing coolant? RX7 GUYS HELP
 

:MissileSm :wallbash: I just got done putting a new water pump in my 86 gxl because of the coolant buzzer and a slight leak of coolant coming from the weep hole. After said and done I thought maybe I put to much RTV Sealant on the WP gasket. Another thing is that I also had a feeling that my water pump bolts were too loose, because even after the new water pump was installed I was still getting add coolant light so I figured i had air bubbles in the system so I burped it and it stopped buzzing. I went for a cruise and I ran it slow for about an hour and came upon an Eclipse so i had to give a taste and I did but boy did I pay, Shortly after at the next light my coolant buzzer started again and I slowly rolled home. When I arrived i popped the hood and I heard a draining noise and then coolant hit the floor, my radiator was popping, my overflow coolant tank was spewing coolant everywhere, and finally I noticed Coolant coming from my water pump gasket and the water pump and the bolts were hand tight. So now I wonder if the loose bolts on the water pump caused the overflow, or the overflow caused the bolts to get loose. Did I blow the motor, the radiator, If anybody has any input is is greatly appreciated. by the way does anybody know if you have to replace your thermostat with a stock one or what thanks guys :wallbash: :MissileSm

Sounds like you have a real problem.

I would first get your water pump issue cleared up. Obviously you have a huge air leak some where. Get your self a new gasket and install that. I dont use RTV if you use a gasket. If you have a problem with the gasket not staying use a little RTV just to hold it in place, and make sure every mounting surface is clean.

After all that is said and done bleed the cooling system, not to sure on how to do that with a FC. Run it a little in the drive way and top of your cooling system. I would replace the thermostat just to save your self some grief. I use mazda stat's but they are spendie and I am retentive.

If you still are having problems with the water coming from the overflow you may want to disconnect your exhaust at the manifold to see if you have water coming from that. If so I think you know what the problem is.

Good luck.

Or use a coolant pressure tested to put pressure on the cooling system to help you find leaks.