[kennyg1958]

Hi All

I have a 2001 GU 4.5l petrol/LPG.
The aircon works fine until the outside air temp gets to around 35c and also stops working if I,m towing on a warm day.
The Air con guy said the systems fine but he checked it on a cool day.
Has anybody got the same issue and what is the fix.

Thanks

 

[BradM]

If it's OK most of the time but when it gets hot outside i.e. you state 35 C it works hard (Maybe due to gas being down a bit) the inside heat exchange unit may be freezing up with ice.

If you turn off the air cond but leave the fan going for about 15 minutes (windows down ) then turn the air cond back on does it work ok until it freezes up again?. If so then you are icing up. If this is correct then either your gas is down or the inside thermostat is not well. There are a few other items but those two are the cheap ones.

Another option is that the drain hole for the condensation is blocked up (inside heat exchanger) and the water condensation cannot get away. This may be drowining part of the inside unit causing efficiency to drop of hugely. Also the inside heat exchanger maybe choked up with dirt that was previously a dust buildup.

The fact that it's ok until it gets very hot outside seems to point to something out of the ordinary.

 

[kennyg1958]

Thanks Brad,
The gas has been checked and is full.
Where is the inside thermostat and how do I clean the heat exchanger.

 

[Sparky_GU]

Sounds like the system could be over gassed and cutting out due to high head pressure.

 

[BradM]

Easy bit is to see if it's freezing up. There are other possibilities too like Sparky_GU mentions, it may be cutting out from high pressure.

If it freezing up very little air will be coming out the vents when it's playing up. If it's cutting out then it's just blowing hot air. Either way you may need to go to another air-cond person who is interested in fixing it for you.

The thermostat unit in the Patrols is usually on top of the inside air-cond heat exchanger behind the glovebox.

 

[Loktndirty]

Your condenser coil in front of the radiator may be chocked with dirt or mud, reducing capacity so it is only noticed on hot days when you really need it. It's easy to get to so I would look there first.

Good time to clean the radiator too...

 

[Smokescreen]

My aircon also cuts out but only if i push the old girl too hard while towing a loaded trailer on a really hot day. I think my aircon cuts out because of a temp sensor??? at the bottom of the radiator which cuts out the aircon at a certain temp as a pre warning to overheating and to help bring the engine temp down. If i back off the loud pedal for a while the aircon will kick back in straight away. Im no mechanic but what iv'e written seems to work in my case.

 

[Baron]

If the petrol engines are anything like the td42, once the water gets over a certain temperature the aircon compressor will cut out so not to over heat the engine.

I have had this happen twice in 4 years, both days I was doing 110kph, battling a strong head wind and the outside temperature was over 40 degrees. Cheers.