Hi all

I'm experiencing air con issue where by on slow traffic is produce cold air but has a "sticky/sweating" feel to it, and it followed by engine temperature raising
(reading digitally in scanguage II) to 100c then the traffic move so it could be higher. Previously, I have replaced the dryer/evaporator and revac the system but the compressor have not yet been change.

On the high temperature issue, this reduces when i turn off the aircon, i have previously changed the radiator/termostat/coolant/coolant reservior. I have not yet replace the water pump and both fans seem to be fine. Both issue only arise in slow to heavy stop traffic, once on the move no problem. Any suggestions please?

Btw, engine has loud humming noise when step on gas also goes with the two above issue when accelerating.

 

Let me suggest that you confirm if your electric fan is working on the AC condensor. AC compressor head pressure impacts cooling, and the electric fan is supposed to switch on at 212F, even lower with AC on (above 83 F ambient and under 60 mph).

That fan should spin freely with no drag. It has a relay and fuse in the underhood box. Fear the blown fuse, it indicates that fan motor has started to sieze.

The main fan should also be checked, warm up the Disco, then turn off the engine. Spin and release the main fan. Should come to a stop in under one revolution. One that freewheels has lost internal fluid, won't produce enough air flow in hot conditions. Fan should also make a "roar" at cold engine start for a short time until fluid circulates.

If your humming noise also happen when you step on gas while in park it may be related to the serpantine belt and something turned by the belt.

 

roger that!
will check and give an update

 

for the ""sticky/sweating" make sure that both evap. drain tubes under the hood are clear. Your AC can run all day but if the condensate can not drain out in a timley manner it is going to get put back into the air.

 

Very good point, and will have that musty smell. Note that when under the truck on each side of tranny there is a rubber nipple, these get clogged with mud on the outside. When you poke them with a stick (just rub the end, don't have to go way up inside), you will "discover" just how much stinky water can rush out on you. This time of year, when in a parking lot, you look for two water puddles from the AC drains. A third puddle, closer to the front, in the center, will be the water pump leaking.

 

This only occurred when temp starting to raise at slow/stop traffic, will check to make sure

 

Not a single puddle underneath, may be that why...but again only occurred when temp on the raise..

 

The extra heat this time of year makes the bacteria and algae grow faster. But as stated, I suspect you have some cooling issues, even if it is something like mud and leaves blocking the fins of the AC condensor and radiator.

Imagine a pan of water left in the garage, and topped off from time to time, but never drained. The sort of swimming pool you would not skinny dip in.

 

Could this possibly be a fan clutch or water pump noise?

 

Will check, it only happened on moving traffic particularly from 1st gear to 2nd gear. The rav counter went to 2K before changing the gear and produce the noise. I have tested when parked the car and raving it but none of this humming/rowing noise what so ever.