Aircon advice please fellow Rangisti.
Aircon was struggling of late so today took advantage of a £36 Groupon re-gas at ATS. Prior to this the car was cooling but would take a while to generate a noticeable difference in a sun-soaked cabin. The re-gas was normal, system maintained a vacuum for the requisite 5 min (indicating no leaks). 780g of refrigerant removed and 890 replaced. Unfortunately since driving for 25-30 min with all permutations of cooling settings I can’t seem to get any cold air from any of the vents.
Engine seems to be idling quite high (maybe anticipating demand of compressor which not coming on line?).
Car is a 2012 4.4 TDV8 Westie.
Appreciate any help prior to taking it back to ATS. Anything you do with common compressor valve failure that I read about here?
Cheers in advance…

Interesting think about a regas and holding vacuum. Whilst the connected machine does test for leaks the one thing it doesn’t test for leaks are the schrader valves on the two connection ports, they have to be open whilst the vacuum is being applied so can’t be tested. I might be wrong but would have thought these two valves should be replaced with new as part of the regas process.
Are they leaking after your regas, who knows.

Sounds like a new compressor job to me. Same symptoms I had. Regassed. No leaks. Wouldn’t cool down. New compressor. Ice cold.
Site sponsor Glenrands did mine  Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
--------------------------------------------------

The refrigerant port valves are not normally changed during a degas/regas, I've seen a few leak but it's very rare.
A vacuum leak check over 5 minutes will only detect the very worst of leaks - one that would usually leave you with no refrigerant whatsoever to recover, even the 30 min. check stipulated by most manufacturers / accredited training establishments will only pick up relatively large leaks.

If the engine speed is raised due to the high cabin temperature, this usually indicates that the control side is functional and the problem is a restriction in the flow of refrigerant if the evaporator temperature isn't dropping, ideally you'd want to be looking at high & low side pressures which is only possible with a manifold set or an 'aircon machine' connected.

Delivered mine to Glenrands this very morning for a new compressor and to get a few other loose ends sorted. 2012 TDV8 Vogue (L322)

Mine rises the rpm as it gets going on start up on hot days Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
--------------------------------------------------

Thanks for all the responses. Very helpful. I’m not too clued up on aircon systems as I normally leave that sort of stuff to the professionals. What I don’t understand is, if I had a working compressor before the regas (temps weren’t ice-cold but indicated a functional system) why would it have failed completely after the refrigerant was changed?

After 16 years of trouble free A/C, my compressor sounds like a bag of nails and struggles to provide requisite cool air into the cabin. Not good in present conditions. Still, do have a sunroof to ease the pain. Previous cars:
S-Max 2007-2013 (only diesel I've had, good car but expensive when diesely bits go wrong, so what's the point?)
Galaxy 2001-2007
Mondeo Estate 1997-2001
Sierra Estate 1993-1997
Uno Turbo 1987 -1993
Fiesta 1984 - 1987
Fiat 127 1982 - 1984

Check underneath with the air con on maximum for a constant drip of water from the air conditioning condenser (the drip is about level with the back of the driver seats). It may be blocked and freezing up.

Secondly, as seems to be the case with the 4.4 TDV8, most of the time, the problems are the same and few, which makes diagnosing quite easy.

If you've got an IID, I would also check in the live values the cabin temperature sensor (note there's several options. One gives 'N/A', one doesn't). It may however be worth cleaning the fan in the cabin temperature sensor assembly.

Thirdly, was it actually working / is working or is it actually intermittent (get the engine above 2,000 RPM for 5 seconds or so and see if 30 seconds or so later icy cool air starts coming out). The usual cause of all manner of A/C problems on the 4.4 TDV8 is the Refrigerant Control Valve (RCV) on the compressor however, to replace it, it involves removing the compressor and at over 10 years old now, it's best to just replace the whole thing, as a new compressor comes with RCV included.

DrRob, JayGee, others and myself have had different issues but all caused by the compressor. Glenrands or Harlands can do the job for you or if you're quite handy, you can replace it yourself and buy a holiday.

I did the job myself and wrote a step by step guide: https://www.fullfatrr.com/forum/post635799.html#635799

Hope this helps. 2015 Range Rover Autobiography 4.4 SDV8

Last edited by garyRR on 18th Jul 2022 8:40pm. Edited 2 times in total

ApeRunner wrote:

.... What I don’t understand is, if I had a working compressor before the regas (temps weren’t ice-cold but indicated a functional system) why would it have failed completely after the refrigerant was changed?

Great stuff thanks, especially for the awesome write up GaryRR. I may summon up the courage to have a go at that.

Pheonix, your explanation of the failure mode of the valve sounds pretty plausible TBH. We shall see tomorrow when I hook it up to a mate's IID.

I shall update...

holding a vacuum in a system that's normally under pressure isnt a really good test for system integrity. 'O' ring seals which under vacuum can be sucked into a seal area, pipe joint faces pulled together etc, when under pressure, they're pushed apart. BMW i3 Electric Car
2012 Full Fat RR 4.4 TDV8 (now gone)
2006 VW Touareg 3.0 TDi V6

When I first had my aircon recharged in my current 2012 4.4 TDV8 a couple of years ago they recharged it as a 4 zone system with 880g of refrigerant and the aircon would not blow cold. The problem it was a two zone system and only required 700g.

Once the refrigerant volume was reduced to 700g the aircon blew ice cold and still does.

I do a complete aircon recharge every spring as a matter of course and it's always ice cold during the hot summer months...

I mention this as the technician recharging the aircon at the time to 880g refrigerant, was unaware of the difference in the aircon refrigerant volumes depending on the two or four zone systems in the L322 and started traying to sell a new compressor and all sorts of additional and clearly unnecessary part replacements.

I mention this as a cautionary tale to evidence that refrigerant volume is critical on the L322. 2012 4.4 TDV8 Vogue SE Current
2015 E220 with AMG Sport Pack - Currently driven by my son
2010 3.6 TDV8 Vogue - Written off by my son

AJGalaxy2012 wrote:

holding a vacuum in a system that's normally under pressure isnt a really good test for system integrity. 'O' ring seals which under vacuum can be sucked into a seal area, pipe joint faces pulled together etc, when under pressure, they're pushed apart.

Yes I'm aware and it's necessary to vac the system out anyway to boil off any moisture and to remove the air.
I'm also amazed at the number of aircon recharge kits around with no gas compatibility checks, no lubrication and no vacuum for an empty system. BMW i3 Electric Car
2012 Full Fat RR 4.4 TDV8 (now gone)
2006 VW Touareg 3.0 TDi V6