A/C pipe burning hot

[meh]

Hey guys My aircon stopped working yesterday while driving along the motorway so had a look at it today. (GU 2001 patrol 3l patrol)

The AC kicks in then within 15 seconds the pipe becomes really hot then AC drops out and just blows as if its turned off. I recently have spent plenty of money having another part of the pipe welded up from a rubbing hole and had it fully regased and since then had no troubles

Below is the pipe in question.. Any ideas ? The engine isnt over heating what so ever

http://i2.photobucket.com/albums/y5/mehhh/work/IMG_3759_zps89bf11cc.jpg

[Yendor]

That pipe should get really hot when the A/C is running.

When the A/C drops out can you see/hear if the A/C compressor cuts out?

Does the condenser fan in front of the radiator come on when the A/C is turned on?

Does the A/C start getting cold again after a period time?

[NP99]

Just looking at the pic, will the ac pipe and radiator rub?

[meh]

That pipe should get really hot when the A/C is running.

When the A/C drops out can you see/hear if the A/C compressor cuts out?

Does the condenser fan in front of the radiator come on when the A/C is turned on?

Does the A/C start getting cold again after a period time? Compressor cuts out and revs drop back to normal. Will check if the condenser fan comes on. The AC is nice and cold for the first few seconds once i have left it off for a little while


AC and radiator doesnt rub at all. I did unscrew the cap from the pic and there were some small bubbles coming out from it and green fluid.

[NP99]

I think the green fluid is so the techs can check for leaks under an ultra violet light of sorts

[meh]

Might just have to take it back to them tomorrow then, was only 4 months since it was fixed!

[Yendor]

It doesn't sound like the A/C system is low on gas.

It could be cutting out if the condenser fan is not working or if the system has too much gas in it.

You could try running some water from the hose over the condenser while the A/C is running and see if this keeps the A/C going.

[meh]

So the aircon guys said there is plenty of gas but the PSI is going through the roof hence the cutting out. They said to try and hose out the condenser for possible mud and that I am missing a piece of plastic shroud from behind my radiator that sits just above the fan so its not sucking in any cool air from outside the engine bay. There was nothing there when I bought the car but can see where its suppose to bolt onto.
Hosed it all out and it was working for about 1min before cutting out and not coming back on again.

[lorrieandjas]

Hi mate - as Yendor said it sounds like an over-pressurised system. However, if you can cool that pipe and it still cuts out I think you have a different issue. I would look at getting them to bleed some gas out and see how it runs then.

Jas

[meh]

Thanks for suggestions. They did tell me though there wasnt too much gas in there. And it had been working perfectly for the past 4 months without fail. until now :(

[Yendor]

Did the so what the pressures where on the low side when the high side was going through the roof?

I think you might need to fit someone else to have a look at it for you.

[meh]

They did but I can't recall they were more interested in telling me I need the plastic shroud

[Yendor]

I think you have more then just a plastic shroud problem.

[meh]

Yes I think so !
Have been keeping an eye on it. Seem's as though as soon as the engine gets to a certain temp it will stop working everytime but still nice and cold while the engine is warming up. Makes me think now it is the temp sensor I was reading about on the forums!!!

[Dominator]

I highly doubt it is the plastic shroud or too much gas. The fact that it was working fine for 4 months and now it is not means something has changed to make it stop working. The high pressure/temperature means it is either a blockage or there is an issue with the condenser. Is there a thermo fan mounted on the condenser or the radiator? Is it working? Also can you check the drier. It is a black canister about the size of a red bull can, it will be somewhere in the engine bay, usually near the radiator. Run the air con and spray some water on the condenser until you are sure it is cooling in the cabin. Then turn the water off and when the air con cuts out check the temperature of the drier, let me know if it is hot/warm/cold etc.

[meh]

Thanks dominator will give it a go today !

[BundyDave]

That pipe should get really hot when the A/C is running.

When the A/C drops out can you see/hear if the A/C compressor cuts out?

Does the condenser fan in front of the radiator come on when the A/C is turned on?

Does the A/C start getting cold again after a period time?

If you can get temps you can plot them on a pressure enthalpy diagram. (Download a program called "coolpack" FREE TO USE AND DISTRIBUTE ). If you can measure suction, discharge end of condensor and end of evaporator pipe temps. Plot these on chart and it will show you what temp discharge should be. If you can get temps I can plot them for you.

If it is too high causes are either overcharged, condensor fan not working or non condesibles in the system. Air may have been introduced whrn it was worked on. Or as said dirty condensor.

Dave

Sent from my GT-N8010 using Tapatalk 2

[Yendor]

Yes I think so !
Have been keeping an eye on it. Seem's as though as soon as the engine gets to a certain temp it will stop working everytime but still nice and cold while the engine is warming up. Makes me think now it is the temp sensor I was reading about on the forums!!!


There are two electrical circuits that will turn the A/C off if temperatures get too high.

The engine computer will turn the A/C off if the engine cooling system is getting to hot and the other one is a pressure switch mounted in the receiver dryer that will turn the A/C off if the pressures in the system is getting to high.

Based on what you have told us (engine is not getting hot and the A/C tech said the A/C high side pressure was going through the roof) I would say it's switching off due to the A/C high pressure switch.

Without knowing what the pressures were on the low side it's a bit hard to guess exactly what your problem is.

The things you need to check are (these items you can actually repair).

Make sure there is no blockage in front of the condenser (plastic bag, mud, grass....etc), no blockage between the condenser and radiator.

Make sure the the electric condenser fan is working and the engine cooling system is working correctly.

Check all A/C pipes and condenser make sure they are not damaged or have been crushed.

If possible make sure water is dripping under the vehicle from the evaporator.

The A/C system it's self needs to be checked and repaired by a qualified A/C tech.

Other possible causes are

System could be over gassed

Have too much oil in.

Could have moisture in the system, this is then freezing and causing a blockage at the TX valve or receiver dryer.

Could be a sticking TX valve.

I wouldn't rule out the system being overcharged as the problem, especially if there is too much oil in the system.

Hope this helps.

Cheers Rodney

[meh]

Got this looked at finally this morning by another person. Narrowed it down to a block in the condensor/ filter so he is fixing on Tuesday so see how it goes from there fingers crossed

[threedogs]

Good to see you're not in a hurry LOL

[meh]

Haven't needed through winter. With summer approaching need to get it done! Haha

[meh]

After all that the tx valve is stuffed too :-(