2012 VW Golf TDi A/C issues

[Seth U]

Hello, First post here. I'm Seth.

I have a 2012 VW TDi

Here's the issues I'm experiencing; A/C blows decently cold when ambient temperature is below about 95 degrees F, but seems to take some time and driving before blowing cold.. Above that temperature, it doesn't seem to work much, if at all. Also, the compressor never cycles off and on. It runs constantly, unless I turn the A/C off which disengages the clutch as it should.

Here's what I've tried; I put one of those cheapy gauges (the type that comes with the Arctic Chill brand refrigerant) on the low side while the system was running and it indicated almost all the way in the red. (about 100F that day/time) So, I let pressure out until it was in the green (judge if you must). No improvement. Added a little back in the system.

Next day, same ambient conditions, I put the actual A/C gauge set on the car. Compressor engaged, low side is 55psi, high side 150. Constant and steady, no fluctuation in pressure at all. I googled what pressure to expect and one source says (for this temperature) the low side should be 50-55psi and the high side around 300. Another source said the low side pressure should be about the same as the temperature. So, some discrepancy there. I decided to add more refrigerant which brought both pressures up by 5 psi. it's now 60 low side and 155 on the high side. No improvement in performance.

Also, when the A/C is shut off the system normalizes to about 120psi in a minute or so. Not too long. Definitely no longer than 2 minutes.

So, I have my guesses, but would like to hear your opinion and experiences. What do you think the issue is?

Thanks guys.

-Seth-

[Cornbinder89]

I'm going to suggest you read through VW eurovan thread ( a few threads earlier on this forum) and look at the pictures of his compressor, If it is like yours, it may be a bad compressor

[Seth U]

I'm going to suggest you read through VW eurovan thread ( a few threads earlier on this forum) and look at the pictures of his compressor, If it is like yours, it may be a bad compressor

Thank you. I appreciate your reply. Advice taken.

Different compressor. Mine has the electronic solenoid valve. (my guess is the valve is the culprit)

Thanks again!

-Seth-

[Seth U]

I should also mention that this system utilizes a TXV.

[Cornbinder89]

So did the Eurovan, but yeah I think the variable displacement compressor is not functioning as it should. I am a heavy truck (semi truck/AG) guy and don't have much experience on the newer cars/pick-ups/vans. I try keep abreast of the latest stuff,

[Seth U]

I hear ya. In any case, I appreciate you putting your 2 cents in Cornbinder89. This is my first run in with one of these newer systems. A little bit of a learning curve coming from the older static orifice and clutched pumps. Pretty sure I've got a decent grasp on the systems operation principals. Plus there's some sources out there that claim VW is known for this issue and the solenoid valve is the fix. It makes sense to me. I went ahead and ordered the Solenoid valve and was going back and forth in my mind on whether to replace the TXV at the same time. But I don't think the symptoms really point to a faulty TXV. But then again, I'm not a HVAC pro.

[Cornbinder89]

In my experience, the Tx valve is very, very rarely the problem. They can get stuck when debris is circulated with a compressor that is sending metal into the system, but to have one be the primary fault is very rare.

[Seth U]

UPDATE:

I changed out the Compressor solenoid valve today and it seems to have solved the issue. The low side pressure is now 30-32psi, the high side is 150-160psi, and it feels to be blowing colder than it ever has before. Today's outdoor temp is only low 80's, so I won't know if it has completely solved all issues until we get some more 100 degree weather. I'm feeling confident though. If it still blows warm when it's hot out I'll come back and update again. If there is no further update after this anyone else with the same issue can safely assume the new valve solved all related issues.

For reference, here's the valve I ordered https://smile.amazon.com/gp/product/B01HC6GZSK

Some side notes:
- In my searches I came across a few sources that claimed the RKX brand valve was the ONLY brand that works properly and is reliable. Even if you or your mechanic puts in a brand new OEM A/C pump, replace the valve with this brand. I just took their word for it and am passing on the info. I can not personally vouch for the comments. Though there are noticeable differences in the part, so I doubt it's just a re-branded item like so many others now-a-days.

- There are a couple different compressors used, even in the same year/model. Double check which compressor you have before ordering. It's pretty easy to see the difference on line then just look under the hood and verify what yours looks like.

Hope this helps someone else out there.

Thanks for the help I got from the guys here! :thumbsup:

[Cornbinder89]

Thanks for the update, that is how we all learn what works and what doesn't. I glad my stuff is all "stone age" and simple!

[Seth U]

Got some 100 degree weather today. Blowing nice 'n cold even without recirculating the inside air. Very happy camper.

[Cornbinder89]

Good to hear!