Air Con Help

[mateus77]

Anyone got any suggestions on why my air con cuts out when its hot outside - above 20 degrees + but is fine when its cooler outside.

It gets cold ok too but when it's very hot it works for a few seconds then cuts the fan/blower and sounds like it is recycling air but not into the cabin. Turning it off and on again works for a few seconds and it then cuts off again.

Thanks for any help...

[TurboBob]

Mateus77 - I have a very similar symptom with my Air Con too! A few weeks ago in August, when it was hot outside, the efficiency of the cooling seemed less than what I was expecting, but it seemed to work. It was slowly deteriorating until last week when it got so bad that when seleced to "LO" it would cool for just 7 seconds and then just blow normal air / warm. I have bought a refill cylinder from HALFORDs with a gauge to help charge the system if needed. With an outside temperature of about 16 degC, the gauge needle sat right in the middle of the BLUE section indicating an ideal pressure, until the air con cycled on, at which point the gauge started to increase well into the yellow section, indicating that the system should be inspected as the low pressure side of the system was getting a bit high. It may be coincidence, but the orange engine management lamp has also come on in the last couple of days. The car is going into the dealer to get its corroded alloys refurbished so I'll get the fault code inspected and the air con looked at. Just hoping that someone can give the heads-up with the symptoms described?

[mateus77]

What corrosion do you have on the wheels?
What model are they / car?? I have same issue with Imola's on my GT TDI - seems a common fault.
Are you having to pay for the work to the wheels?
Let me know the diagnosis on the air con, thanks.

[jnv]

Anyone got any suggestions on why my air con cuts out when its hot outside - above 20 degrees + but is fine when its cooler outside.

It gets cold ok too but when it's very hot it works for a few seconds then cuts the fan/blower and sounds like it is recycling air but not into the cabin. Turning it off and on again works for a few seconds and it then cuts off again.

Thanks for any help...

Hi there, is your condenser fan working when a/c is switched on?
The smaller fan on back of radiator I believe is the condenser fan. If this fan isnt working the pressure will build up due to no air flow cooling the gas and cut a/c on/off

[Pit Dweller]

Yep, check to see if the smaller fan is working, it's there to cool the gas, if fan isn't working pressure in system reaches over 30bar, ECU then cuts compressor signal to stop any damage. When pressure drops, compressor starts working again.

[mateus77]

Is it expensive to fix??
Thanks

[jnv]

Hi, I don't know much about cost I'm afraid, I have yet to ring VW for a cost of parts.

The condenser fan doesn't work on my car (2.0tdi gt140). I have yet to check voltage at the fan to see if it is the fan or something further back like a bad connection or broke fan control box or fuse

If it is the fan, looking at my car the radiator has to come out or at least moved forward some to get the plastic cowling off and that looks like a good hour or two to put right.

[TurboBob]

What corrosion do you have on the wheels?
What model are they / car?? I have same issue with Imola's on my GT TDI - seems a common fault.
Are you having to pay for the work to the wheels?
Let me know the diagnosis on the air con, thanks.

The aircon problem was down to the 10A fuse (F24 under the bonnet near battery) which had blown. Good call Pit Dweller and jnv. When I first replaced the fuse, it ran OK until I stopped the A/C and then restarted it again. As it looked like a fan current start-up issue, in cowboy fashion, I replaced it for a 15A fuse, just for 30mins. It ran fine, without blowing on starting, and then replaced it with the proper 10A fuse. Now working fine. Beautifully cool!!!

The update to this post is that the failure of the air con fuse was found to be NOT down to an over-current in the fan motors but something else - apparently, the same fuse, F24, also drives the Intake Flapper Motor or Throttle Actuator Controller. A couple of days after the original post, when the fuse began blowing again, I found this out by Googling about and found the Pierburg Service Information note SI0095, http://www.ms-motor-service.de/ximages/pg_si_0095_en_web.pdf. The symptoms of the Engine Shudder at ignition off are described correctly, it's just that I hadn't associated them with the original problem. When my £ 99.00 OBDII code checker was plugged in to find out what the cause of the MIL lamp was, a P2108 code was shown, which is a "Throttle Actuator Controller (TAC) Performance" problem.

After changing the TAC unit (1 connector and 3 bolts) the MIL lamp could be cleared and stayed clear. When the ignition was turned off, the engine stopped nice and smoothly, without the judder.

TAC unit was £ 187.00 from Euro Car Parts. Job done.

Then I wanted to know what could have gone wrong with the old TAC unit - the old unit had part number 038128063G and yet the new TAC had same part number but with an "M" instead of a "G". So I decided to open up the old one to see what you gets for your money.
7078

7079

7080

7081

7082

Reckon it was oil contamination - just need to find out how it happend before the new TAC goes the same way!

Mateus
The Alloy wheel corrosion I'll put in the appropriate thread which has already been started.

Cheers

[jadefour2000]

Anyone got any suggestions on why my air con cuts out when its hot outside - above 20 degrees + but is fine when its cooler outside.

It gets cold ok too but when it's very hot it works for a few seconds then cuts the fan/blower and sounds like it is recycling air but not into the cabin. Turning it off and on again works for a few seconds and it then cuts off again.

Thanks for any help...

Hi Mateus,
Did you ever got to the bottom of your aircon issue? Was it the smaller fan? Both my fans works ok, but has exactly same issue yours has got which might be different from what TurboBob has.
Any help and I appreciate this thread is old.

[rowdy-999]

Hi Mateus,
Did you ever got to the bottom of your aircon issue? Was it the smaller fan? Both my fans works ok, but has exactly same issue yours has got which might be different from what TurboBob has.
Any help and I appreciate this thread is old.


Get it scanned.It will show any fan, or fan controller issues.

[jadefour2000]

Hello, Scanned and found Actuating Motor for Temperature flap, left (V158)

Both small and big fans works fine.
This issue is more pronounced during hot days @20 degrees an above and more pronounced when the Lo input for the climate control for the driver side is selected (right-hand drive car)
No probs with hot temperatures.
However my compressor pulley makes a pronounced squeaky each time I select the lower temperature with the Econ button not selected.

The main issue is the flap shutting down with the blower making a recirculating noise but with almost no air coming out of the vents. If I Hit the Econ button, I get a rush of air but not that cold which means the vent opens up and when I turn Econ off, the vent shuts down again and I get the recirculating of air sound from the blower.
Everything works fine for a few minutes but then goes pear-shaped and would only work for less than a minute going forward at every reset (turn climate control on and off or press the Econ button on and off).

This is a very confusing one, as I don't want to open up the dash to replace the Actuating motor when it doesn't need changing. It works fine with heat, Econ apart from when the Lo input is entered for the driver side and then the vents shuts down.

Any help please.