D3 Air con trouble

[Bowyang]

I have a strange fault in the air con of my 2005 TDV6. Sometimes it works perfectly and is quite cold, other times it is just cool, and yet at other times it can be ambient. The air temp can go through all three temperatures in 10 minutes. Other times it stays cold as it is set.I have had the gas topped up and the only fault showing is the cooling fan is running fast. It engages very shortly after engine start - even from cold. Any ideas please.

[LandyAndy]

My Bro is having the same issue on his D4.
Diagnosed as a faulty valve on the pump.Has been advised to replace the pump as a complete unit.
Being the tight arse he is he is trying to locate a new valve.
Andrew

[ytt105]

I think its called the TX valve.

What happens is the evaporator actually freezes and you cant get any air flow over it. Turn the air con off of five minutes and it will defrost and then the air will flow over the cold evaporator.
Mine does it once every blue moon, I think it happens when the outside temp goes up very quickly.

Regards
Trev

[LandyAndy]

I think its called the TX valve.

What happens is the evaporator actually freezes and you cant get any air flow over it. Turn the air con off of five minutes and it will defrost and then the air will flow over the cold evaporator.
Mine does it once every blue moon, I think it happens when the outside temp goes up very quickly.

Regards
Trev

In my Bros case the aircon takes along time to cool,yet sometimes its OK.No freezing of the evaporator as its still cooling.
His gas and pressures are good.
Andrew

[scarry]

The valve in the pump(compresser) is a completely different part to a TX valve.

Google is your friend,it will save me explaining the difference.

In short,

The compressors are unloaded,and loaded as needed,with a valve,which is probably the valve Andy is talking about.This is usually the issue in the D3/4.New compresser needed,expensive☹️(what item isn't in these vehicles?)

The TX valve is the main expansion device in the system.

There can also be many reasons why an evap freezes over,not just a fault with the TX valve.

[Bowyang]

The compressor cycles on and off as it always has. Would it necessarily do that with a crook valve?

[LandyAndy]

The compressor cycles on and off as it always has. Would it necessarily do that with a crook valve?

My Brothers also cycles on and off as it would in the past.
Andrew

[scarry]

As far as i know the compresser is permanently engaged,variable displacement.(unless i am wrong):o

Same as all modern AC systems,even our crapota vans are the same design.

So if it is cutting in and out,something else may be wrong

[LandyAndy]

Paul,I though the same.My Bro says the clutch on the front starts/stops like a normal AC pump.His is an early 3.0 D4.
Andrew

[BobD]

Paul,I though the same.My Bro says the clutch on the front starts/stops like a normal AC pump.His is an early 3.0 D4.
Andrew


My early (2009 build) D4 had the same problem. The compressor is variable displacement and when they wear the pressure to operate the valve which controls the variable displacement is too slow to build up pressure. both the valve and the compressor will be worn to cause this.


They don't cycle. The clutch is to stop the belt breaking if the compressor jams from what I have read.


I would highly recommend a new compressor. If you look up all the problems with VDC air cons (Land Rover, VW products and others) you will see that the compressor usually fails not too long after it starts playing up, even with a new valve.


On the 3.0l D4 the compressor is virtually inaccessible, whether to change the faulty valve which is in the compressor or the compressor itself. It took 2 full days to replace mine through a tiny hole underneath the car in front of the left front wheel. You can barely get your hand through the small opening to work on it but they did manage to change mine and it is now all fixed. I won't tell you the cost though! Kevin did mine, or at least the air con guy they use did it.


I requested a new compressor to fix my issues after it took ten minutes to start cooling on the way home from Rovertech on a 40 degree day after just spending significant money getting it regassed and the air con guy saying it was working perfectly.

[LandyAndy]

An Update.
My Bro had his done yesterday at All Cool Components in East Perth.
Its a $20 generic valve,compared to a $350 Land Rover item.
When they remove the valve if there is no black crud the compressor is OK.
Job cost $370 including de-gassing and re-gassing,there was no black crud in his.Running 3degC at the vents now.
Job took around 2 hours as he waited.
Common issue on many vehicles apparently.
He did say he would send a pic,I will add it if it turns up.
Andrew

[LandyAndy]

Here is the control valve,it does have wires but they were broken during removal.Had to result to blowing the valve out with nitrogen apparently.Its not a TX valve.Handy to know its common to other aircon systems,just got to find a decent auto fridgy who knows his stuff.Well we have one in WA it seems:cool::cool::cool::cool::cool::cool::cool:
https://www.aulro.com/afvb/images/imported/2017/04/1002.jpg (http://s113.photobucket.com/user/LandyAndy_2006/media/Mobile%20Uploads/2017-01/IMG_1436_zpshduyt9vb.jpg.html)
Andrew

[LandyAndy]

BUMP for G5k.
Andrew

[GP1200]

I'm have the same / similar problem since Christmas, air con was taking 3 - 4 minutes to start blowing cold air, ( is basically blowing warm air on start up during the day ) and once working normally is no where near as cold as it used to be. Where as before you nearly needed a jumper on when it was cranked on low, now it feels like I'm living in Darwin during summer!

had it checked out during it's last service and they couldn't fault it ( gas correct ) now have it booked in in two weeks for further testing.

it seems a few are having similar symptoms-it looks like the extended warranty is going to pay for itself after all, ( 2013 D4 )

do we know what they call this potential valve / switch ?

thanks
Jack

[LandyAndy]

Same issue it seems.
If you have a warranty go the whole hogg with the compressor like the dealer wants too.
My bro had normal values on his pressures too.
At best warranty gives you a new compressor at worse you head down to East Perth.Give them a call,they will tell you what it is.Its not a TX valve,that is on a normal system,this is to do with Climate Control systems.
The tip is don't keep using it like it is,it will destroy the compressor my Bro was told.
GOOD LUCK
Andrew

[g5k]

Andrew bumped the thread for me as having similar issues. My mechanic assessed it as compressor replacement. He said the compressor is effectively choosing to stay in neutral at times instead of kicking in. To us it has seemed to work okay most times at moderate outside temps and then when it's hotter outside less likely to provide any cooling at all. But since having the car has never been icy cold just assumed being a British car they don't really need much in the way of cooling so that was how it was. Thanks for the assistance Andy will run this past our mechanic.

[BobD]

The valve is called the Displacement Control Valve and is controlled externally on the D4 by an ECU. It is what controls the displacement of the variable displacement compressor.

Its good to know that it can be replaced so cheaply, given that the compressor is so difficult to access and the valve is part of the compressor. However, my research indicated that these valves usually fail because of a failing compressor and will often fail again in a fairly short time. Hopefully, in the case of Andy's brother, they are correct that the compressor is OK and doesn't need replacing. As I said earlier in the thread, I replaced my whole compressor since it was getting up in kms, with around 220,000km on it. The air con people said there was nothing wrong with it but when the car wouldn't cool for several minutes on a hot day and once it got going the cooling capacity was much less than normal, it is obvious that there is a problem.

When working correctly, the D4 air con starts straight away and cools the car incredibly well on the hottest days. The days where English air cons were useless are long gone, at least in the case of Land Rover.

[LandyAndy]

Bob.
My Bros D4 has very similar Ks to yours,he tells me the aircon is now the best he has had in a vehicle.Perhaps he has bought time,who knows.
Yes,the D4 has a bloody good aircon,you look at the player comfort meter on the dash and say it cant be that hot out there,then you touch the window,or worse have to get out.OH yes it is that hot out there!!!!
Andrew

[GP1200]

I put my little Engel fridge thermometer in the dash air con vent today, basically the best it would get was less 15c than the dashes out side temperature during the day, ( it was about 32c in Perth today )
The coldest it got during the drive home from work was 8c after nearly 45 minutes of driving and outside was about 27c. ( it was hovering 12 to 15c most of the time )

What should it get down to normally ? I'm guessing how it feels in the car about 3c would be normally
working D4 air con system ? I have a HSE, do they have anything extra to power up the rear air unit or just more plumbing?

Do they normally stock the air con compressor at Southerns ?

Jack

[BobD]

Yes, the D4 air con is definitely the best I have ever had. Only the short time where the DCV was playing up that it wasn't. The DS is also very good but not quite as powerful as the D4 I think. I remember Falcons where you were barely cooled on hot days and I hired a Colorado 7 in Adelaide a couple of weeks ago which wasn't much good either.

[DiscoJeffster]

Got a quote from the place in East Perth. They wanted $825 to replace the compressor’s electronic control valve. Same symptoms as the others with slow to start cooling. Pressures measure fine, no indication of the Black Death.
I’m going to try and fix it myself, taking it to get it degassed, will replace the valve and regas. My only concern is whether I can get the valve out without air pressure. We’ll see how I go [emoji846]

Oh and for whatever reason the 3.0L has a clutch unlike the other models.

[letherm]

I have a HSE, do they have anything extra to power up the rear air unit or just more plumbing?

Jack

I have an HSE too and I seem to recall that it has a separate unit for the rear aircon. Vague recollection of it being in the nearside rear wheel arch cavity. Wouldn't bet the house on it though [smilebigeye]

Martin

[scarry]

There is a rear Fan and evaporater coil in the compartment above the left rear wheel arch.
One compresser under the bonnet serves both evaporater coils.

[kevo78]

Just thought I'd add another one to the list, I've got a 2013 110k thats doing this so i'm hoping it's only the valve, getting a bit tired of repairing this bloody thing. Hey Andrew any updates on how your brothers is doing?

[DiscoJeffster]

I have a valve on the shelf I need to fit. I’ve heard it’s helped by extracting the Gas, undoing the locking circlip, then pressurising the system with nitrogen which ejects the valve pronto!

[g5k]

I had my valve replaced and fixed the AC. 2010 model

[DiscoJeffster]

I had my valve replaced and fixed the AC. 2010 model

I’m going to get someone to extract the gas, refill with a little nitrogen for positive pressure, swap the valve myself, then take it back for a regas

[g5k]

I’m going to get someone to extract the gas, refill with a little nitrogen for positive pressure, swap the valve myself, then take it back for a regas

Sounds good you’ll save a heap my cost a bit (it was quoted) never found out if it took as long as the estimate. Should take a photo guide as you do if you can be bothered for others in the future.

[kevo78]

Anyone got a part number at all for the valve? D4 2013?

[haydent]

Anyone got a part number at all for the valve? D4 2013?


D4 A/C Compressor issue (https://www.aulro.com/afvb/l319-discovery-3-and-4-a/268239-d4-c-compressor-issue-post2876735.html#post2876735)

[loanrangie]

D4 A/C Compressor issue (https://www.aulro.com/afvb/l319-discovery-3-and-4-a/268239-d4-c-compressor-issue-post2876735.html#post2876735)

I think after 4 1/2 years hes either sorted it or moved it on.

[haydent]

I think after 4 1/2 years hes either sorted it or moved it on.

clearly by the fact that I just posted here, theres more users than just him looking at this thread...

[DiscoJeffster]

There is no LR part number. You’ll need to confirm the brand of compressor then go for a google. It’s likely a Sanden, but get the details to confirm. I got mine from the US.

Don’t waste your time though. Just change the compressor.

[haydent]

Yes im going to replace my compressor, but there are LR numbers in that document