VCDS AC Diagnosis

I am a relatively new to the TDI world. I made my purchase back in November and now that its warmer weather I am having AC issues. I have read and learned tons from the forum in the last few months. I genuinely appreciate all of your input and time that you guys have put into the library of information.



Symptoms are:
Intermittent Cold Air (mostly cool-warm)
Constant High-ish Engine RPMS = Cooler Air


I took it to AC mechanic and he said it needed complete compressor, condenser, and expansion valve replacement.


He did not mention anything about replacing just the RCV, but after a little research I may give him a call and ask him about replacing it. I may replace it myself and have him drain and fill system.



I have gathered some values from the VCDS. The AC system does not have any active or prior fault codes. Does anybody have an input based on the values posted in below? The car was running at idle speed.


Refrigerant Pressure - 8.6 Bar
Compressor Shut Off Req. - Compressor active
Compressor current -.82A

Compressor Speed- 1000/ Min
Compressor Load- 3.7 NM
Coolant Fan actual- 26.8

Coolant Fan activation- Specified 20.8%

Outside Air Temperature- 28 C
Temperature after evaporator- MUX -25.7
Compressor shut off last- Outside air temp too low




On a side note is the dryer included in the condenser or is it a separate part?



Thanks in advance.

Edit your post and remove the picture. On my computer it came out at 30 pages of jibberish.

I replaced the RCV on mine and fixed the problem. You have to make sure to order the correct one. need to get the brand and part number off the compressor. was able to see mine easy with the plastic under the car removed. If you remove the RCV and its plugged up with grey goo then you do need a new compressor. good luck....

Seems to be a MKV/MKIV plague with these cars - seems to not be if it happens but when.

My '12 is getting a whole new compressor under CPO warranty next week. Dealer tried to evacuate and recharge the system and pass it off as fixed, I didn't even move the car from where they parked it for me to pickup, just walked back in and told my service advisor to come outside and I would show him it still is not cooling.

It worked great if I could keep the engine speeds at 2k or above - dropping back down to idle or creeping in stop and go traffic it went back to maybe a few degrees below ambient temp.

update

[FONT=&quot]I figured I would try the RCV sensor. I ordered it from Polar Bear Inc. and I spoke with him on the phone. He was really helpful and the support he provided for his product was great. He was able to give me some good pointers and some things to look for when removing the sensor.[/FONT]

[FONT=&quot] 1. Look for dirty or gummy oil = compressor on its way out. [/FONT]
[FONT=&quot] 2. Look for metal shavings = dead compressor [/FONT]
[FONT=&quot] 3. Remove the serpentine belt and spin compressor by hand (after Freon has been removed) = if it moves freely without grinding and crunching then the compressor is probably good. [/FONT]


[FONT=&quot]After I did Polar Bears recommended checks I replaced the sensor and had the Freon filled and was driving to work with 37 degree air coming out the vents this morning. The sensor worked for me. Replacing the RCV saved me a headache and about $1100.00. The sensor was $62.50 and the freon fill was $50.00 at a local shop.
[/FONT]

I do about 20+ of these a year, very common.

There is finally a TSB from Volkswagen on them, too. So you CAN order the new RCV by itself from Volkswagen, and they really shouldn't be replacing many compressors under warranty OR customer pay. As this is almost always the fix for the problem, and it is super easy to do.

oilhammer said:

I do about 20+ of these a year, very common.

There is finally a TSB from Volkswagen on them, too. So you CAN order the new RCV by itself from Volkswagen, and they really shouldn't be replacing many compressors under warranty OR customer pay. As this is almost always the fix for the problem, and it is super easy to do.

Click to expand...

Do you have the TSB number?

JELLOWSUBMARINE said:

Do you have the TSB number?

Click to expand...

2044165 or 87 16 19 is what it shows. And that one is dated October of 2016, so it isn't exactly "new".

I am an hour and half away from dealer. I am not sure how they handle the TSB's. I didnt want them to look at it and tell me it wasn't the RCV and I would be stuck paying the diagnostic fee and still have no AC. Have you guys had good luck with them handling the TSB's honestly?

They will plug your VIN into OTIS, and see what applicable TSBs come up. Your car should be in there. If they bother to do even this.

I cannot comment on how they handle them, as it could not be the same at every dealer. Any shop that has an A/C recovery/recycle/recharger machine for R134a, some Torx bits, a 16mm socket, and a pair of snap ring pliers, and a pinch of common sense, can swap an RCV in one of these. Super easy.

AC is giving trouble again. It works and ac drops to 40 degrees it just takes about 8 minutes. Seems to cool faster if I drive faster or the engine is at higher rpms. Should I remove refrigerant and RCV valve again? Do I have any options? Has anyone tried removing the valve and replacing it again?

Did you draw a vacuum on the system? If there is any air in there it will cause problems later on.

Yeah, my mechanic drew a vacuum before I replaced the valve. I replaced the valve and took it back to the mechanic he drew a vacuum again and then refilled using the recovery machine. I hooked it up to VCDS yesterday and all is well. I looked at everything I knew to check and it looked good. The AC is working it is just really slow to cool. I don't know what to do. I have a feeling the compressor is good because it works really well once it starts working.