Mitsubishi Repair: Overheating problem, water coolant, coolant system

Question
'93 Eclipse, 2.0 Engine, 130,000 miles, Auto Trans: Had major engine work (bearings, valves, etc.) done a year ago. But, now the engine loses water/coolant and overheats after being driven about ten miles @ 60 mph. It has no visable leaks; new hoses; and thermostat. Radiator was recently flushed. After idling to normal temperature (with cap off) water/coolant gushes out. There is no water/coolant in crankcase and new head gasket was installed when engine work was done, so I doubt that the head gasket needs replacing. This car has not been driven while "hot". THANKS!

Answer
Wayne,
Sometimes after major engine work has been performed, the head bolts can work their way loose, which can allow some water to enter the combustion chamber and burn off in your exhaust.  You may want to have someone follow you as you drive on the highway to see if there is evidence of white smoke escaping from your tail pipe.  Have a compression test done to be sure no gaps developed in your new head gasket.

Also check to be sure your overflow tank has the correct amount of coolant when the engine is warm and cool.  If there are is excessive amount of air in your coolant system, then coolant can get pushed to the overflow tank and get spit out through the dump tube.  You would not notice this driving at high speeds, but it's possible that it could happen.

If you check those items and still cannot find the problem, you may need to have a shop perform a pressure test on your coolant system.
Good luck!