Just bought a 93 Civic from a friend of mine who i work with, says he has replaced the Thermostat but car still over heats. there is no visable leak when pouring in coolant. although he would drive approx 12 miles and the car would blow coolant out of cap. what the possibilities? i bought the car for $700 hoping its not a big issue. Thanks in advance!

 

I would remove the cap and inspect the fill neck area(s) for any sort of crack in the plastic (assuming you have an OEM, or OEM-style plastic end tank radiator). Also, inspect the hoses for leaks/stress cracks.

If no cracks, I would suggest to replace the cap. It is a $5-$10 part from a local auto store. As long as the coolant system has been bled properly, the fan turns on, you should have no problems. If the motor was overheated previously, there is a possibility that the head gasket is shot in addition to the head being warped.

Let us know what happens, or if you have any other questions.