When I park my car after driving coolant runs out of the overflow tube. I drained the system, refilled with Prestone radiator flush, ran it for 60 minutes with the heater on, drained and flushed again with water and refilled with anti-freeze and distilled water. Still happens. The temp gauge reads normal and it doesn't smell or sound like it's overheating.
I'm stumped....any suggestions? Thanks!