So My 91 RS (305) began to overheat. Naturally i replaced the thermostat first (185). I noticed the fan was jogging on the motor shaft so i replaced it with a universal fan (hayden brand). I did a radiator flush and it is STILL overheating (260+). There is no water coming from the weephole of the water pump, this is the only part of the cooling system i have not changed or flushed out. I do live in Phoenix where its 110+ for 5 months of the year which is when this issue popped up. is it just running hot due to outside temp. Or is there something I'm missing or could try? Anything will help at this point

 

Is your cooling fan kicking on at all and if it is ,when?

 

I have it wired to turn on with the car.

 

Fans on and still overheating? Wow! I wonder if there's something wrong with your pump or if coolant is even circulating thru the engine, can any other members chime in?

 

When its warm enough for the thermostat to open try to squeeze the top hose to see if its flowing coolant from the thermostat

 

Also did you check to make sure the air dam is still there