overheats

howdy- i have an 00 intrigue and it runs like a dream- at least until tonight. i was driving home, getting off a highway and my engine heat started creeping up. i pulled into a gas station parking lot not too far from my house, turned my heaters on, and popped the hood. it cooled down for a...

The car only begins to over heat while driving, not in idle. The temperature drops when the RPMs go up (Like at a stop to acceleration) but then begins to heat up again when cruising. This is what my mechanic and myself have done. *Water pump was leaking. Replaced *Coolant Flushed, filled...