Thermostat is about 2 years old.
Radiator is about 6 years old.
Just changed the radiator cap 2 weeks ago.
Just bled the system 2 weeks ago.
Not leaking from water pump, or radiator.
No milky oil, or residue in radiator/reservoir.
No white smoke. Heater blows hot.

My driveway has an incline. Backing down the incline I noticed the gauge went up. Driving uphill also cause this same effect. Idling made it go down.

However, driving down the road without the a/c on, everything is fine.

Any help?

 

water pump?

 

Why would it be? I don't see it leaking from that area.

 

Does it have to leak to be a problem? Could there be a possibility that the blades on your water pump are corroded and broken apart floating around your cooling system? Could there be a possibility that you aren't using "coolant" and just plain unfiltered, non-distilled, water? I don't know that? Could there be a possibility that your headgasket is leaking? Could there be a possibility that your fan isn't really kicking on?

NO ONE KNOWS.

 

50/50 coolant has been used the entire lifespan of the engine. So we're going to rule rusted blades out.

Everything else you inquired about has been posted. Thanks for your guess though.

 

Well I'm already tired of playing guessing games, GL.

 

Did you confirm rad fan is turning on, also confirm both fans running when A/C is on.

If all good it points to a worn out water pump, you did not mention MM&Y of car and regardless of coolant used, water pumps, like anything else, will ware out over time.

With that said when A/C is on there is a lot more heat going through the rad from the A/C condenser, going uphill adds load to the engine, so question is when you say "overheating" what exactly do you mean, what does the temp. gauge read? 94

 

OP - Read the forum rules sticky.

Car information is required for ALL tech threads, and you must politely answer questions asked by members trying to help.

LOCKED.