Hills and temperature

[ZachFD]

I might just be nuts, but it seems like my water temp always reads higher when I'm on an incline than on a decline....not necessarily under a climb, even when sitting still.

I was cruising on the interstate in 100F temps the other day at 70mph, my fans were on and my temp was around 195F. All was fine until I hit a slight incline on the interstate...temps started creeping up to 215F so I turned the heat on...dear god my skin roasted but temps dropped back to 200F. As soon as the slight incline was over, temps dropped immediately back to 195f.

Car NEVER used to do this with fans on when I had it all stock. It would sit at 185F all day long. My only mods are SMIC/Large Aluminum Duct for I/C, Aluminum intake pipes, Airpump delete, DP, Koyo radiator. Could all the aluminum cause heatsoaking?

Same thing happens on hill when I am sitting, like at a light on a hill with fans on...my temp will climb from 185F and start climbing until I face downward.

Does this sound like a slipping waterpump/poor circulation...maybe on an incline, gravity is pushing the water to the back of the radiator/motor and pump can't keep up? I do have the stock wp pulley w/ airpump removed. If I try to turn it, I can with my hand, but the belt still gets enough grip to rotate. I have a larger pulley ready to put on.