My 2000 WRX Wagon is overheating really quickly when driving hard and cooling really quickly. Any ideas out there. A Novice.

DO YOU ALSO KNOW IF IT MATTERS WHICH TYPE OF DUMP VALVE TO FIT. I been offered a Forge..

 

Check the condition of the coolant, if it looks a bit ****ty, drain the system and refill with coolant (through the top rad hose to try and avoid air locks).. If you still have the same problem then remove the thermostat and test it in a pan of boiling water.

If its cooling back down then hopefully its not a head gasket.

 

Do the fans come on?

Any bubbles in the coolant?

Does the heater get hot?

What level is the coolant?

sounds like early signs of the head gasket, hope I'm wrong

 

As for dump valve, if you want a vent to air valve go for a double piston one. doesnt matter what brand it is really.