ok guys, huge problem
87 CRX si d15a3 with a/c is overheating. It stays at a very cool temperature for about 15 minutes of driving, then starts to heat up, both the ac fan and the cooling fan are in perfect working order, i just changed the thermostat and rad fluid with a 50/50 mixture. The only way I can get the car to cool down is to run the heater full blast which isn't great in 90 degree weather. I dont have a headgasket problem as there is no oil in the water or water in the oil. It doesnt leak fluid at all nor does it overheat whilst idleing. What seems to be my problem?

 

Waterpump?

 

i figure the only way you know a water pump is failing is it wont pump any water or it leaks, its timing belt driven so if its not spinning then either is the camshaft

 

Right, but the internals (fins/impeller) could be corroded, and or it could be leaking, etc.

 

have you checked radiator level? just because you dont see visual of mixing fluids doesnt mean its not bad. my crx never shot out smoke never mixed fluids but always overheated. pulled the head off and the gasket sure was bad. replaced it and never over heats

 

Head gasket is always my first thought in this situation, but figured the guy did his research on the gasket.

Check oil/water lvls and color. Do a compression check on all cyl to see if you have any discrepancies between cyl. Check your plugs for moisture or fouling., etc...