Golf MK5 Aircon Issue

[jamesh89]

Hi guys,

I've recently picked up an 06 Golf GT TDi 140 with Climatic control (not the dual climate) and having some issues with my aircon.

It's not blowing 'fridge' cold air like my last mk5. I've had a re-gas but no change unfortunately.

I've got no fault codes showing with VCDS and have obtained the following from the HVAC measuring blocks:

-Compressor shut off code = 0 (which I believe indicates compressor running)
-Compressor speed = 1000/min
-5.4 bar refrigerant pressure
-10.0% Radiator fan Activation (actual)
-0% Radiator fan Activation (Spec)
-19.0c Footwell blower temperature (when temperature dial on minimum!)

I note that neither of the cooling fans start up with the air con on, though they do fire up when running the engine output test in VCDS - I've not heard them going in any other circumstances though. I'm wondering if the difference between actual and spec above points to anything?

Any suggestions where to go next?

Cheers in advance!

[Crasher]

Without having the special testing gear required it is impossible to check the compressor properly but from your data I would say your compressor regulator valve has failed. You can buy these separately but the best method is to fit a new quality compressor from Denso.

[FLAPPERJACK76]

Did you get this readout with engine running ac on max cooling? 5 bar refrigerant reading is what you expect to see with engine off and ignition on . Its worth looking at compressor current and nm output. You also need to be in measured values 08 hvac.

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[jamesh89]

Hi guys, thanks for the quick responses, much appreciated!

I feared it could be compressor but was hoping it was something more simple. Water muddied slightly my HVAC measuring values as suggested Flapper. No current registering in the actual box - does that just suggest my controller doesn't support? Also, pressure slightly higher than yesterday which was under similar conditions, engine running and max fans. The outlet temp wouldn't fall below 22c. Finally, relating to the fans, I noticed than although they spin in the output tests, no RPM registers! Quite puzzled by all this now!

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[FLAPPERJACK76]

I think you should be seeing some actual current. Check the plug on the regulator on the compressor. Based on the what you have wrote though a pressure of 5 or 6 bar on the high side and an output of 1.9 nm ( i can fart harder than that) would indicate your compressor is doing sod all.

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[jamesh89]

Hahaha thanks Flapper, I'll have to take your word on your output pressure! I'll check the plugs on the weekend but everything is pointing to your's and Crasher's diagnosis that the compressor is the issue. Pressing the Econ button in the car registers no change in temperature telling me that you're exactly right, compressor doing sod all!!

And to think I've just sent my old mk5 to the salvage yard with a fully functioning compressor! Rookie mistake...