Temp gauge

[1995 brian]

Alright so coming home from work theres a steep hill and everytime im passing threw it the cars temp goes to 3/4 instead of staying in the middle and once im done climbing the hill it will cool back down to normal temp slowly. What do you guys think this could be? It happening in my 1997 gsx awd auto.

 

[Ferrarieater]

First guess is clogged radiator.

 

[Colt4G63 also]

I have the same problem, especially when I have the A/C on. I have tried cooler thermostats, drilled thermostats, copper radiators, aluminum radiators, a huge aluminum racing radiator, ducting, different fans, hood vent, heat wrapped manifold, straight water, water wetter, heat shields, etc. etc. but nothing works. I'm starting to think my water pump impeller is shot.