So, I just picked up this car last week, so cheap I practically stole it. 95 Mystique GS, V6 auto, 115k mi. It had a busted temperature gauge, and the owner thought it was overheating- it's not. Here's what's up...

Put a brand new temperature sending unit on the car. This fixed the temperature gauge problem. But, it's running hot. Pointing at either the A or the L in Normal, depending on how hard I've been running it.

I put a new thermostat in it and flushed the radiator. It didn't change a thing.

I'm fairly certain the car has no head gasket issues, as no matter how hard I run it it will not go above the L. I live in the Appalachians, and can take the car up a mountain at 75 with my foot to the floor the entire time, and the needle will creep from the A to the L but go no higher- and rapidly drops back to the A after I ease up on the throttle.

I'm not smelling any coolant. Coolant tank is full, and the coolant is circulating. Can't see any coolant leaks. Water pump looks good, no seepage or wobble in the pulley. No steam from under the hood. No water or smoke from the tailpipe. Heater blasts hot, but running it has no effect on the temp gauge. The engine runs smooth as silk, with plenty of power. No coolant in the oil. No oil in the coolant. Cooling fans kick on as the needle hits the M.

Any suggestions? I can't find a thing wrong with this car, and this temperature problem is driving me nuts!