almost overheating while a/c is on (1 Viewer)

[jgray]

Its been hot lately... When running my air conditioning lately my temperature gauge starts climbing... If I turn it off and keep driving it returns to normal... Anyone have this same issue??? Fan clutch? Thermostat? Opinions appreciated as always...

 

[FRESHLC100]

How old is your coolant? Could be thermostat. Have Dealership diagnose.

 

[jgray]

Coolant is all good. Recently changed with the red Toyota oem red stuff. I don't mess with the stealership for anything either. I just hit 150k on my 99 100 but and did alot of preventative maintenance inlcluding new timing belt water pump power steering pump alternator coolant etc etc. I had it in some pretty deep mud recently on a wheelin trip but have cleaned it pretty thoroughly since we got back.

 

[spressomon]

Its been hot lately... When running my air conditioning lately my temperature gauge starts climbing... If I turn it off and keep driving it returns to normal... Anyone have this same issue??? Fan clutch? Thermostat? Opinions appreciated as always...

Put a ScanGaugeII on it and get actual temp readings.

Have you inspected both sides of the radiator fins for dirt/mud/accumulated debris that would reduce its ability to transfer heat? Just in case you don't already know: Don't power wash the radiator fins! Hi pressure hoses can actually bend the fins!

Does it overheat at idle or while running down the highway at 65mph? If only at or near idle (or at lower speeds) it might be your fan clutch starting to fail. When the engine is hot turn off the engine and immediately try to turn the fan. It should be very difficult to turn if the fan clutch is locked up. If not its a simple fix: You can remove the fan clutch and drain what's left of the factory silicone out of it (usually need to do this overnight) then refill with new silicone (the silicone breaks down overtime and provides more sheer...). There are a few threads in the 80 and probably 100 section about this...

What does the radiator look like? Did you do the flush? If so what did the evac'd fluid look like?

 

[tommy854runner]

My vote is the radiator. I buried my Tundra in the mud one time(stupid teenager stuff) and it started to overheat on the way home. I washed off the radiator the best I could but it still overheated. I climbed underneath the truck and removed about another 19lbs in mud off of it and it was fine. Just my 2 cents.