1999 Pathfinder Temp gauge goes Up

[jackman]

My temp gauge goes up to the hottest extreme on occasion when I put on the A/C. It will then go away after I put the heat on and shut off the car for a day only to happen again some time later.

I have put in a new thermostat and water pump as well as had the radiator checked for clogging and any leaks.

Any thoughts?

[Dano]

I moved it to this forum, where hopefully you'll get a better response!

Wondering if the A/C cycling switch may have something to do with it? Check your A/C condensor to make sure there's not a significant blockage anywhere in front or in the fins.

[alms24sebring]

A/C fan

[fueler]

alms24sebring, there is no separate dedicated A/C fan on this engine. The AC condenser is cooled by the main engine fan, which is driven off the water pump using a thermo-mechanical fan clutch. The fan clutch is supposed to stiffen up when the car gets hot, cooling it down more. But you're on the right track.

i would check the fan clutch. With the engine hot, (and shut off), spin the fan. If it spins more than one revolution freely, than the fan clutch should probably be replaced. Also, you can hear a good fan clutch when the engine gets hot. Mine sounds like a school bus turbo when i use AC. (i use a TorqFlo fan clutch from autozone which spins harder than stock and has lifetime warranty).

I'm not saying this is your problem, but it is worth checking.

Also, if youve done any muddy offroading, take a garden hose and flush the radiator fins from the back (engine side) to the front. Obviously try not to bend the fins.

[alms24sebring]

Even tho the engine fan is there, most cars still have a high speed fan on the radiator/condensor. Good example.. 240s.

Im not saying all cars or this model pathfinder have this setup, Im not positive. But those would be the 1st things to check

Any updates?

[fueler]

240 is a good example of something irrelevant

[jhong1226]

if it only does it when ac is on, good chance its the fan clutch.

[Chuck Tribolet]

Does it do it with the AC on and running down the highway at 55+, no stop lights?
Does it do it at stoplight, AC on?

If the answers are no and yes, it's fan-related.

[jackman]

I brought it to a different place today and they cleaned out a "ton" of leaves tucked between the radiator and the condenser.

I am hoping this takes care of it.