Summer has hit in the great plains and my temps are way up. I've been running above 200 degs on the interstate. With temps pegging up to the 220's. I am planning to rip apart the VX to replace the waterpump, hoses, timing belt and tensioner sometime next week.

I was wondering if the thermostat might be to blame. Is there a test to find if the thermostat is working right? I really don't want to dig that far under the manifold to replace it if I don't have to. Anybody know of these failing?

Or should I go ahead with the maintainence I have planned and see if the coolant flush fixes the problem.

Oh, one more thing. The radiator is clean, washed it down just the other day, didn't really help the problem too much.