The Brick-yard Homepage Brickwerks
Forum Home Forum Home > T5 Section > T5 Chat
  New Posts New Posts RSS Feed - Diagnosing A/C Problems
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Diagnosing A/C Problems

 Post Reply Post Reply Page  12>
Author
Message
stalbansdragon View Drop Down
Groupie
Groupie


Joined: 02 Mar 10
Status: Offline
Points: 63
Post Options Post Options   Thanks (0) Thanks(0)   Quote stalbansdragon Quote  Post ReplyReply Direct Link To This Post Topic: Diagnosing A/C Problems
    Posted: 12 Jul 11 at 10:47
I'm probably going to sound stupid now but need some help diagnosing my air conditioning problems...the problem being it has suddenly stopped working!  It was emptied and refilled last year and has been brilliant until recently.

What I'm after is some help diagnosing the problem.

The A/C light still comes on when I push the button but no cold air.

I get no fault codes recently  - though I previously had error codes about an intermittent fault with the pressure sensor (whilst the air con worked).

The results from VAG Com output tests are:

Current : 0.5A   Load: 62.7%   Torque 1.0Nm  Absolute Pressure 4.4 bar.

I don't know where the compressor is to see if it is switching on and off but can't see the revs dropping when idling and I put the A/C on.  Can anyone let me know where the compressor is?

Any help diagnosing the problem would be very much appreciated.

Back to Top
energysolutions View Drop Down
Vanorak
Vanorak
Avatar

Joined: 02 Dec 08
Location: Earth (For Now)
Status: Offline
Points: 3684
Post Options Post Options   Thanks (0) Thanks(0)   Quote energysolutions Quote  Post ReplyReply Direct Link To This Post Posted: 12 Jul 11 at 11:18
1.9 or 2.5?
!!Never Eat Yellow Snow!!
Back to Top
The Transporter View Drop Down
Vanorak
Vanorak


Joined: 08 Nov 05
Status: Offline
Points: 1012
Post Options Post Options   Thanks (0) Thanks(0)   Quote The Transporter Quote  Post ReplyReply Direct Link To This Post Posted: 12 Jul 11 at 15:35
First thing to do is to have the weight of refrigerant checked.. There can be a point on warm days where there is enough refrigerant vapour pressure to not fire up a fault code but not enough refrigerant volume to do any cooling. High side and low side refrigerant pressures would be good too whilst the system is running at 1500rpm.

My 54 plate 2.5 hasn't dropped a gram of refrigerant, I know 'cos I checked it a little while ago but then I do run the aircon constantly
2004 174bhp AXE engine..... Belligerence has been confirmed.
Back to Top
stalbansdragon View Drop Down
Groupie
Groupie


Joined: 02 Mar 10
Status: Offline
Points: 63
Post Options Post Options   Thanks (0) Thanks(0)   Quote stalbansdragon Quote  Post ReplyReply Direct Link To This Post Posted: 12 Jul 11 at 19:58
2.5 174bhp
Back to Top
The Transporter View Drop Down
Vanorak
Vanorak


Joined: 08 Nov 05
Status: Offline
Points: 1012
Post Options Post Options   Thanks (0) Thanks(0)   Quote The Transporter Quote  Post ReplyReply Direct Link To This Post Posted: 12 Jul 11 at 22:55
The compressor is on the right hand side low down on the front of the engine (As you look at the front of the van) but it is a shit garbage clutchless compressor so without refrigerant gauges it is tricky to tell what it is doing...
2004 174bhp AXE engine..... Belligerence has been confirmed.
Back to Top
stalbansdragon View Drop Down
Groupie
Groupie


Joined: 02 Mar 10
Status: Offline
Points: 63
Post Options Post Options   Thanks (0) Thanks(0)   Quote stalbansdragon Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jul 11 at 11:39
Thanks for help so far.

There are two connectors on the right hand side of the engine bay near the top that look like pressure gauge points.  Which is the high and which is the low pressure?
Back to Top
VW master-tech View Drop Down
Yardie
Yardie
Avatar

Joined: 28 Aug 09
Location: bedfordshire
Status: Offline
Points: 407
Post Options Post Options   Thanks (0) Thanks(0)   Quote VW master-tech Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jul 11 at 00:10
Hi before you get to drawn into checking gas pressures, wiring and such would be well worth see if the compressor is turning it is driven by small rubber belts (gates couplings) via a one way clutch the clutch and collapse, or the gates couplings can shred causing the compressor not to turn and no ac if you drop off the undertray you can see the compressor and some of the coupling.Hope it helps.
Back to Top
T5 TDI View Drop Down
Vanorak
Vanorak
Avatar

Joined: 05 Nov 05
Status: Online
Points: 3369
Post Options Post Options   Thanks (0) Thanks(0)   Quote T5 TDI Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jul 11 at 19:27
Originally posted by VW master-tech VW master-tech wrote:

Hi before you get to drawn into checking gas pressures, wiring and such would be well worth see if the compressor is turning it is driven by small rubber belts (gates couplings) via a one way clutch the clutch and collapse, or the gates couplings can shred causing the compressor not to turn and no ac if you drop off the undertray you can see the compressor and some of the coupling.Hope it helps.
 
Thumbs Up  I agree with that.  What mileage is yours?  I don't think we have seen a single Gates coupling failure at less than the official 80,000 service time.  Although if the compressor has siezed that would strip the teeth on the coupling whatever the mileage.  Search on here, it's not an easy job though...
 
2004 2.5 174
Back to Top
stalbansdragon View Drop Down
Groupie
Groupie


Joined: 02 Mar 10
Status: Offline
Points: 63
Post Options Post Options   Thanks (0) Thanks(0)   Quote stalbansdragon Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jul 11 at 14:06
Thanks - I checked gas pressure before reading the replies - and all is fine so that's ruled it out.  Guess is a dodgy pressure sensor or a problem with the compressor.  Time to take the bottom tray off as suggested by VW Master-tech I think and see if the compressor turns.

My mileage is 95k so gates coupling renewal is due in 5k.


Edited by stalbansdragon - 18 Jul 11 at 14:07
Back to Top
gregozedobe View Drop Down
Vanorak
Vanorak


Joined: 22 Dec 06
Location: Canberra, Oz
Status: Offline
Points: -998435
Post Options Post Options   Thanks (0) Thanks(0)   Quote gregozedobe Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jul 11 at 14:57
Originally posted by stalbansdragon stalbansdragon wrote:

My mileage is 95k so gates coupling renewal is due in 5k.


Actually I think that makes it overdue ........(but most seem to last a bit longer than the official change distance).

Edit 19 July 2011:  I was wrong, the current official distance is 180,000Km (see later post for full mea culpa).


Edited by gregozedobe - 19 Jul 11 at 07:00
Back to Top
stalbansdragon View Drop Down
Groupie
Groupie


Joined: 02 Mar 10
Status: Offline
Points: 63
Post Options Post Options   Thanks (0) Thanks(0)   Quote stalbansdragon Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jul 11 at 15:13
My book states it is due at 100k miles.

I've dropped the tray off and had a look but can't see anything damaged.

Assuming the A/C compressor is as marked as '1' in this photo I can't see an damage.  The black bit marked '2' in photos turns freely.  However when I start the engine and put the A/C on it doesn't turn.
Back to Top
The Transporter View Drop Down
Vanorak
Vanorak


Joined: 08 Nov 05
Status: Offline
Points: 1012
Post Options Post Options   Thanks (0) Thanks(0)   Quote The Transporter Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jul 11 at 17:26


Were the pressures taken with the engine running and the air con on? what were they? what ambient temperature?

If the shaft that goes into the compressor rotates with the engine running then the couplings are ok and you are looking for a problem elsewhere


Edited by The Transporter - 18 Jul 11 at 17:27
2004 174bhp AXE engine..... Belligerence has been confirmed.
Back to Top
stalbansdragon View Drop Down
Groupie
Groupie


Joined: 02 Mar 10
Status: Offline
Points: 63
Post Options Post Options   Thanks (0) Thanks(0)   Quote stalbansdragon Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jul 11 at 17:37
Just tested and the temperature is 17C and pressure is showing as 65PSI (seams high to me!)

I wasn't very clear before....Looking at number 2 on my photo, nothing rotates when the engine is running however it isn't seized - I can rotate it by hand with the engine off.  Should I be able to see something turning, or is the shaft hidden inside?


Edited by stalbansdragon - 18 Jul 11 at 17:51
Back to Top
stalbansdragon View Drop Down
Groupie
Groupie


Joined: 02 Mar 10
Status: Offline
Points: 63
Post Options Post Options   Thanks (0) Thanks(0)   Quote stalbansdragon Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jul 11 at 18:21
Ah! - now I think I have found the problem and think people are right - it looks like the gates coupling has gone

To the right of the clutch (?) labelled 2 in the photo is a coupling with the rubber band on.  One side of this turns but not the other.  I'm guessing the teeth on this rubber have stripped.  Luckily for me the A/C compressor isn't seized so cost should just be the gates coupling service that was nearly due anyway.

Thanks for everybody's help on this.



Edited by stalbansdragon - 18 Jul 11 at 18:46
Back to Top
T5 TDI View Drop Down
Vanorak
Vanorak
Avatar

Joined: 05 Nov 05
Status: Online
Points: 3369
Post Options Post Options   Thanks (0) Thanks(0)   Quote T5 TDI Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jul 11 at 19:02
That's it then.  Smile   If yours shows as a 100k change they must have altered that because the earlier ones are all listed as an 80k change as Greg says. 
2004 2.5 174
Back to Top
gregozedobe View Drop Down
Vanorak
Vanorak


Joined: 22 Dec 06
Location: Canberra, Oz
Status: Offline
Points: -998435
Post Options Post Options   Thanks (0) Thanks(0)   Quote gregozedobe Quote  Post ReplyReply Direct Link To This Post Posted: 19 Jul 11 at 06:58
OOPS, I just checked on the current official advice from VW Australia:

In the current "Service Schedule - Commercial Vehicle: (the official one from my VW dealer only a couple of weeks ago) it states:

"T5 R5 engine: Renew gates coupling and freewheel for alternator and air conditioning drive 180,000km" (= approx 111,111miles)

So it seems we should also be replacing the freewheels as well as the gates couplings.  Mind you, I'm not sure I'll still have my T5 when it gets that old.

Interstingly the schedule for passenger vehicles states that the DPF for the V10 Touaregs should be "renewed" at 120,000km, but doesn't mention the DPF for the R5 engine version (which is basically 1/2 of the V10).

Back to Top
stalbansdragon View Drop Down
Groupie
Groupie


Joined: 02 Mar 10
Status: Offline
Points: 63
Post Options Post Options   Thanks (0) Thanks(0)   Quote stalbansdragon Quote  Post ReplyReply Direct Link To This Post Posted: 19 Jul 11 at 08:33
I've just booked mine into Wayside Dunstable and he listed the parts used in the Gates coupling service to me and mentioned the freewheel as well - so looks if you go to a VW place they replace that as well....but a good point for those doing it DIY.
Back to Top
VW master-tech View Drop Down
Yardie
Yardie
Avatar

Joined: 28 Aug 09
Location: bedfordshire
Status: Offline
Points: 407
Post Options Post Options   Thanks (0) Thanks(0)   Quote VW master-tech Quote  Post ReplyReply Direct Link To This Post Posted: 19 Jul 11 at 23:59
Glad you got it sorted stalbansdragon you say you have it booked in at wayside is that for them to do the work or just supply parts if you are down stick your head in the workshop and say hello im the master tech there ask for andy.
Back to Top
stalbansdragon View Drop Down
Groupie
Groupie


Joined: 02 Mar 10
Status: Offline
Points: 63
Post Options Post Options   Thanks (0) Thanks(0)   Quote stalbansdragon Quote  Post ReplyReply Direct Link To This Post Posted: 20 Jul 11 at 16:38
Getting Wayside to do the work (rather than just parts).  Am dropping it off on 28th - will say hello.

I've just had a thought - I said the A/C compressor wasn't seized because I could spin the black bit marked 2 on the photo.  However, does that actually mean it hasn't seized or is there some internal clutch which would mean the compressor shaft could be seized and the black bit marked 2 could still spin?

Last thing I want is for a seized compressor to be found when doing the gates coupling and me having to pay for a new compressor.  If it needed replacing I'd rather source one myself from an accident vehicle or similar.
Back to Top
virgobugs View Drop Down
Groupie
Groupie


Joined: 24 Sep 09
Location: Saltash
Status: Offline
Points: 47
Post Options Post Options   Thanks (0) Thanks(0)   Quote virgobugs Quote  Post ReplyReply Direct Link To This Post Posted: 05 Aug 11 at 21:58

I lost the aircon on Caravelle a while back and it tuned out to be the Air quality sensor (Climate control). A few weeks later it stopped again so I scanned and no faults.

After a bit of searching on web found out about the gates couplings which it turned out to be!
@ 64K with full service history!!
 
Took some pics of the job so i'll whack a how to togeather soon.
 
A quick vid to show waht sholdn.t be happening!!
 
 
 
55 Plate Caravelle Executive 174BHP
Back to Top
 Post Reply Post Reply Page  12>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 11.10
Copyright ©2001-2017 Web Wiz Ltd.

The WebThis site