ok so i have a 92 civic dx 1.5l sohc car has been over heating for a while now i have been changing part by part ive replaced the radiator, fan motor, thermostat, water pump, and the cooling fan switch. After all this the car still seems to over heat. when it over heats the temperature fluctuate if the car is given gas, also after i get the car cooled down after this occurence every time the water levels are running low however i can find no present leak. Also this will not happen usually if i just let the car idle it is only after it is driven i can leave it at an idle outside for over 30 mins and the car temperature will sit pointing at D3 like it is supposed to, thanks for taking your time to read this if you have any suggestions please feel free to post im willing to try almost anything at this time.

 

Likely there is a leak in the engine, such as the head gasket. When the engine runs, exhaust gas is pushed into the cooling system and displaces the coolant. To check this fill the radiator completely and leave the cap off. Start it with the radiator cap off and rev it. If a bunch of gas blows out of the radiator, that is the problem.

 

i have already jacked up the front end to bleed out the air in the system with cap off saw no evidence of gas or oil in the cooling system i had running for 30 minutes and the fan cycled 3 times, also found no evidence of water in the oil. checked the spark plugs they were dry although i still replaced them just in case, also have replaced the plug wires, compression is also fine.