I have an 87 rx7 gxl. overheating problem. I put in a new radiator, thermostat, clutch fan, engine has 8000 post rebuild, waterpump about 4.5 years old ( and appears fine), new sending unit...
but when I use the A/C and run the car down the road at 3000 RPM's the gauge goes up to 7/8 ths full. I used a laser gun and the engine was at 218 ...
is that too hot or does the gauge need replaced thanks Alan

 

Short check list: Did you use a Mazda oem thermostat, do you have the radiator shroud and undertray in place, what weight of oil are you running, is your oil cooler good and how's the timing?

 

turns out it was the water pump... even though it appeared "healthy"...