2006 mountaineer temperature gauge spike when a/c is turned on

[darens67]

Hey Folks

I have a 2006 4.6 3V Stock Mountaineer. Driving for a couple hours, turn a/c on and temperature guage climbs to top of High. Shut off a/c and temp guage goes back to normal. Did this 10 times during a 6 hr drive and exact results happened 10 times. Car has 59,000 miles, bone stock, and antifreeze was changed last year. Btw the antifreeze is full both in overflow and raditator.

What is the problem. Any help would be greatly appreciated.

Regards
Daren

 

[NoFear95]

Seems strange the AC should not cause that kind of strain on the cooling system at all. I think there is an issue with your fan clutch not engaging fully when the AC system is on. Mine clicks on full blast when the AC is on. I live in Phoenix az and summer time is 115-120 easy. I can pull a trailer, with four people and gear up the mountain with front and rear ac blasting and I have no cooling issues. I also have the tow package etc.

But something tells me its a fan clutch issue.

 

[mechanic62]

I agree with NoFear on the fan clutch, if you checked first for ANY obstructions at the condenser and radiator. Also, the air deflector under the rad support plays an important part.

 

[vipersinu2]

does the gauage go right to hot if you try the ac first thing in the morning the trucks engine is cold it would take a few minutes running to overheat, if it spikes right up it might be eletricical? get a thermometer and check temperature of coolant maybe guage is not reading right.

I would not let the motor get hot, the heads will warp and head gasket will fail

 

[darens67]

Ok, I checked the fan (when car is cold) and the fan spins freely. When car is cold, gets a/c fine with no temperature guage spike. I need to check if fan spins freely when hot and need to get air dam on bottom. When guage gets pegged does an idiot light also come on or is it just the guage.

I have stock 2006 mountainner 4.6 3V 6 speed.

Thanks
Daren

 

[NoFear95]

Its not a matter of it spinning freely, is the clutch engaging when the gauge climbs? You should "hear" the fan when the AC is on in the garage etc. It should roar pretty good when the engine gets warm and the AC is on.