Mitsubishi Repair: Engine Overheating!?!, blown head gasket, hydro carbons

Question
I have a 1993 mitsubishi eclipse 1.8 liter engine non-turbo and have recently been having an overheating problem. I had recently been having this problem soon after the winter, which i think may be because i now have the heater off and not cooling the liquid that cools the engine off anymore. One day driving about 30 miles to a neighboring town my engine overheated and at a stoplight the engine got real hot and then pushed all the coolant/water out of the resovior bottle and then as soon as the light turned green i pulled over to cool the engine down. Hence once getting the car home keeping a good eye on the temperature i changed out the thermostat, hoses, radiator, water pump, belts, and flushed the coolant out about five times now through all that. So to recap, when the engine overheats it seems to be when i drive a long distance and then come to a stop and sometimes when driving on the highway. I had also noticed that when the engine overheats passed the halfway mark between cold and hot the fan seems to stop functioning properly. So now i checked the relay and have the sensor terminal shorted to keep the fan on. I have not yet driven the vehicle to determine whether the problem is because of the fan, or in the long run the thermosensor. I am at a loss for words and need desperate help to determine what the problem is. I had called some nearby shops and they told me that it could be a blown head gasket, there is no smoke coming out of my tail pipe or any water in my oil or any oil in my coolant. It does, however, seem that my coolant is disipating, which may be a blown gasket. If there is anything that i missed please let me know. I am a college student pressed for cash and if anything that is to be done, more than likly will be done by me :(. Another questions i have is, is there any way that i could tell that there is a blown gasket other than a pressure test. For example a chem test on the coolant to determine if there are any hydro-carbons in the coolant? Thank you for your time.
Pantaleon Vieyra

Answer
Pantaleon,
To check for a blown (or possible just warped) head gasket, you can perform a leak-down test.  This is typically done by forcing compressed air into the intake and listening where it comes out.  It's not too easy unless you're a bit inventive and have access to an air compressor.  I do not know of any checmical tests to check for this.

But the symptoms you've described do sound like they point to a blown head gasket.  I've seen this happen on other Eclipse (older and newer) where there is no evidence of oil, coolant, or any other leaks on the ground or out of the tail pipe.  The leak past the gasket may be just slow enough to be burning off a slight amount of coolant out of the exhaust without visual detection.  So it may be necessary at this point to replace your head gasket, which seems to be the only thing you have not replaced yet in regards to fixing an overheating problem.
Good luck!