what would cause it to run hot in stop and go traffic?

The fan is not working. When it is on the freeway at speed plenty of air flows over the radiator to keep it cool. In stop and go traffic it needs a properly operating fan to move the air across the radiator.

Check your electric radiator fan; l have changed more than l can count on 96-2000 dodge dakotas and caravans. A overheating problem that is encounterd in traffic usually indicates a failed fan; disconnected radiator shroud, or a dirty radiator. But my money is on the fan this time.

Sounds like ur radiator has a leak.it is common on cars that r about 9 years old. When ur car is cool, like sitting for a view hours, u can look at the radiator to see if it is low, look at ur owners manuel for the proper antifreeze, or just add water.

At Highway speeds the air coming into the engine is enough to keep it in operational temps, but at low speeds there is not as much air, so the liquid in the radiator & the fan do most of the work of keeping the car engine cool. If it is low it cannot do this job properly.

If it was my car l would add antifreeze to the radiator to the maximum recommended level & monitor it for a week or two to see it there is a significant drop in fluid. If so it is a leak somewhere. It may be a hose which would be relatively cheap to fix, or if u have to replace the radiator about 200-300 at a good mechanic.

Be sure to take care of the problem before major damage happens to ur car. And if it is the radiator it is worth getting fixed, instead of going out & buying a new car.

As others have said it may also be the fan, with the car running pop the hood & see if the fan is moving.

l do not want to be smart, the obvious issue is cooling & fans. However we must also consider the transmission, it gives off tremendous heat & should be cooled, but l think it is in ur exhaust system too, read about Aero exhausts.

You will hear the 2 fans by the way, if they come on, A/C fan comes on first in my Caravan, well before rad fan!

Also, change coolant, since it turns to sludge or mud in less than 10 years - big difference with new 50/50 antifreeze.

its the fans or low coolant, thats why you probably notice it get hot when your in traffic. the coolant isnt circulating as fast as it does when on the highway.

the most common cause of what yours is doing is either the fans are not working right on it or the radiator is getting stopped up on it,when the bottom of the radiator gets stopped up it wont allow the coolant to flow real good through it and that will cause it to heat up in town and slow driving but run cool on the freeway.you have to remove the radiator though to have it flushed out right or it wont help it none,good luck.