My car is trying to overheat when I leave it running for more than a few minutes in neutral, when driving, it's just fine.....I checked the fluid level, fine, fans are turning on also....what do you guys think? Is the water pump going out, or maybe the thermostat?

Also, the coolant in it is pretty old, and dirty...should I just do a full coolant flush first?

 

If its the thermastat you can see if the coolant is circulating throught the radiator by removing the radiator cap. Make sure its not hot when you take the cap off. You might want to flush the system if its been that long.

 

Describe "overheating". Normal operation is sometimes mistaken for it.

 

While idling @ a stop, it just slowly creeps near the red. I've seen normal operating temps, and it has never got that close to the red. When I start moving, the temp. starts falling again.

 

My car does the same thing. I always thought it was normal though.

 

I would check to see if there is air in the system. There are two bleed valves on the highest two points of the cooling system. One is on the hose going to the top of the water pump and another right near the thermo. Get the car started from cool, let it heat up just a bit (if it's too hot you'll just spew coolant) and pop those bleed valves a bit, if any air comes out, it's air in the system. Also do the same after the car is cool and the air has had a chance to come to the top of the system. If you hear any hissing, then there was air in the system.

 

How near the red? Are you sure your fans are operating at this point? It does not sound like it.

When you start to go again, you are getting air flow across the radiator. If the fans were really on, they would already be having the same effect.

If the fans are not coming on, it could be that the temp sensor in the water pump is not giving the correct into to the pcm so it will turn the fans on. Any chance you have a scan tool to monitor the temp the pcm sees?