90 Exc 22re Truck

[ricknzan]

I recently had the radiator, fan clutch and thermostat replace in my 90 Toyota truck. Since then the temp gauge goes into the red intermitantly during all kinds of driving conditions, climbing, traffic, level etc. Sometimes if I down shift and increase the RPMs the gauge drops. When I turn the truck off the gauge falls immediately. There is no loss of coolant and no other evidence of overheating other than the gauge. My mechanic suggested replacing the thermostat. I did this but the problem still persists. Anyone out there have a clue? Thanks! Rick :ffs:

[Tom.B]

Maybe it could be the water pump? or the belts are not tight enough. Just you said the guage drops when you rev more.