AC woes

[Knoxville]

I've been having issues with my AC system on my 2011 TDI Jetta. Been going on for about 16 months now. I finally took it a local shop that works on a lot of imports and had them check it out. I'm told that the compressor is not making enough pressure. On the high pressure, they said it's supposed to be around 250 PSI. When the compressor was running, it only got up to about 130 PS. The low pressure was about 30 psi and I believe they said it should be around 60.

My first thought would be to add a can of freon, but they tell me the system is "full".

Any thoughts on this?

R&R the AC system through that shop is $1200.

 

[dzldawg]

It may be the pressure switch. My 06 had this problem. Does it work at all? Mine would work after putting it on auto at first, then when it started cooling I could put on whatever setting I liked. Where in Knoxville did you take it?

 

[Knoxville]

I'm actually in Joplin, MO. The username Knoxville is a reference to my home, which is locked down like Fort Knox. I had a buddy try to make it through my security and he made the comment, I'm getting out of Knoxville before the 5.0 shows up. So it stuck. Sorry for any confusion on that.

I took it to Auto Haus in Joplin. I felt like they've been very reputable in the past, but now I question that. I stopped at O'Reilly's and put a half a can of freon in it. Gauge on the low pressure went up about 15 psi to 45 psi. It's colder now than it's been in a while. I'll give it a week before I'll confirm it's working. But if a 20$ can of freon is all it took, I have some burning comments to say. I wonder how many other people they tell it will take 1200$ to fix their car when they could spend 20 bucks at O'Reilly's and save the expense. That pisses me off.

 

[jetlagmech]

have you seen the threads on the RCV ? Refridgerant Control Valve. it controls output of compressor. if this valve sticks compressor output is low. can be changed without removing compressor from car but does require freon evacing. most manuals dont show it as a cangeable part. VW doesn't even stock it. I'm not claining to know more that the shop because you might have a bad compressor. Just another possibility.

An RCV change seems to have fixed my car A/C underperformance issues although will find out for sure soon as it starts hitting 110+F next month.

 

[Knoxville]

My Jetta is an auto. Do you have a part number of the RCV? Or if you have some good threads saved, I'd appreciate a link. Otherwise, I'll just search for a while this evening. Thank You! Any ideas on how to diagnose a bad RCV? I have an authentic copy of VCDS where I can hook up my Jetta if needed.

 

[bennybmn]

My AC quit a year ago, and I read a lot about the RCV too. Thing is mine stopped during a trip where I literally left the house under warranty, but ticked over 40K a couple hundred miles in!! If I find any old threads, I'll link them here. I'm interested to find an alternate source for the valve too, just in case.

 

[jetlagmech]

I bought my RCV online from polar bear inc. also sometimes called Compressor Control Valve. My biggest problem was finding someplace willing to change it. Most large A/C shops wont mess with something not in the book.

I didn't want to just vent the freon into the air. I try to be a little enviromentally concious about stuff. my great-grandkids will have to live in the world we leave them.

as far as which one. Polar bear has a pretty good description with compressor part numbers to determine which one you need. I was able to read the compressor part number with a mirror from under car.(and reading glasses.....getting old sucks)

the shop I found to change it just had me order the valve myself. If they pull the valve and its covered in grey gook then your compressor is shot.

 

[Ol'Rattler]

I stopped at O'Reilly's and put a half a can of freon in it. Gauge on the low pressure went up about 15 psi to 45 psi. It's colder now than it's been in a while. I'll give it a week before I'll confirm it's working. But if a 20$ can of freon is all it took, I have some burning comments to say. I wonder how many other people they tell it will take 1200$ to fix their car when they could spend 20 bucks at O'Reilly's and save the expense. That pisses me off.

Just throwing a can of freon at it isn't the answer. Something is not working correctly or is leaking and needs to be repaired. If the system is working correctly, freon does not just leak out.

Oh, I tend to stay away from O'Reilly's for anything except candy bars and car wash products. Just can't stand to put any of their garbage Chinese products they sell on my car.

 

[mj1053]

I took my 2011 Jetta TDI in today for the 60K maint. My wife mentioned the ac wasn't blowing cold as start up, but eventually would get colder. The dealership said the compressor was out. I'm thankful I bought the extended warranty from First Guard (6yr/120K) for $1700. My only complaint is when they called today First Guard said they would have to come out and verify the $1400 quote to fix the ac system. Now I'm in a gas jetta with no tint. I'm a little peeved at First Guard. The mechanic stated he's seen 3 additional 2011's with bad compressors lately.

 

[Black_Smoke]

It may be the pressure switch. My 06 had this problem. Does it work at all? Mine would work after putting it on auto at first, then when it started cooling I could put on whatever setting I liked. Where in Knoxville did you take it?

This is my bet. If there was something wrong with the compressor, it would just run and run without building pressure. If it builds pressure to 130psi then kicks out, it's likely the pressure switch.

 

[Tuco]

Mine will blow cold if I put the fan on high and let it run for @ 5 minutes. When it starts blowing cold, I can turn the fan down to 3 or 2 and it will stay cold. If I turn the fan on low it just blows warm air.

That makes me think it has enough R134 and the compressor works, but I have no idea why I have to run it on high for it to blow cold.

 

[d2305]

http://forums.tdiclub.com/showthread.php?t=413320

 

[Black_Smoke]

http://forums.tdiclub.com/showthread.php?t=413320

A leak would probably cause the pump to run continuously as well. Is the compressor clutch disengaging?

 

[d2305]

The compressor doesn't have a clutch so it runs all the time.

 

[Black_Smoke]

I'm pretty sure there is:
http://photos4.automanager.com/021908/images/vw_2_0_tdi_103kw_140ps_10.jpg

 

[d2305]

http://forums.tdiclub.com/showthread.php?t=253641

 

[Black_Smoke]

http://forums.tdiclub.com/showthread.php?t=253641

Cool, I've learned something new for the day! So that big monstrosity of a pully is just there to keep all of the parts together if the compressor locks up.

Can you view the state of the pump displacement in VCDS? If so, you could still find out if the pump is capable of reaching the desired pressure or not.

 

[d2305]

Since I think mine has a leak, a thermometer in the vent and titrate with 134a until about 40*F is the fix until it won't cycle.