GOLFMK8
GOLFMK7
GOLFMK6
GOLFMKV

Ac troubleshooting

orangeman

New member
I have a 2011 GTI with ac not working. I have worked on the ac on other vehicles but this one is different. I've been googling for days and can't find info I need to troubleshoot. Looking for help.
So the ac worked fine 1 day next day I start up and no ac. I can't even tell if the clutch is engaging as there is a rubber cover over the end of the pully that blocks the view. Normally I would jumper the relay to force compressor on and check pressures but no relay on this system. The low pressure port pins my guage which leads me to believe sys is charged but compressor is not running.
Looking for advice on how to move forward. I have a multimeter and know how to use it.
 

orangeman

New member
Ok I purchased a VAG401 clone(more than worth the $50.00) and got 1 trouble code showing bad recirculation flap motor. Fixed this and cleared code still no AC and no codes. Took a close look at the compressor and the shaft was not spinning. Turns out the shear plate had let loose. Compressor was not bound up so considered just replacing the plate but could not find a source for the plate as it is different from the ones available on ebay. Found the exact same PN compressor on a car at the local pick n pull swaped the compressor in recharged the system and AC is working. I did not replace the dryer or any other parts but only opened the system for a few minutes and pulled a vacuum for several hours. Time will tell but so far so good. Best info on ac troubleshooting I found was on the Ross Tech forums.
 

orangeman

New member
Didn't even know what an overrun pulley was till it took out the second AC compressor clutch plate. I replaced the AC compressor with a salvage yard unit . It worked for a month then the pulley sheared again. Compressor would spin freely and was not seized so went looking for another cause. What I found is that the alternator overrun pulley was frozen up and would not allow overrun. I had been getting some strange noises occasionally when starting from a stop and engaging the clutch . I first thougtht it was a boost leak or clutch chatter or exhaust rattle just couldn't figure it out.
If your compressor pully shears and the compressor still spins freely be sure to check the alternator pulley before replacing.
 

orangeman

New member
OK Last update. I was able to order a new shear plate for the denso compressor from a Chinese website. The old shear plate hub did not want to come of and the central shaft end with 7MM bolt pattern got stipped. I had to drill a hole in the hab parralllel to the shaft and drive a screw driver into the whole to split the old hub off. Its all back to together and working well.

Hope this help someone else out it sure did take alot of time to track everytthing down and get it fixed.
 

clockwise33

New York Giants Fanatic
Thank you very much for this thread. I just fixed my neighbor's 2013 GLI with this issue. They were about to have the compressor replaced and I was able to save them a lot of money by putting in a used alternator with properly operating freewheel pulley (original one had seized) and picked up a used compressor which I swapped the pulley over from. AC up and running again for $130.

If anyone has a sheared AC compressor pulley on a TSI, first thing you need to check is if the alternator pulley free spins in one direction, if not, that's the culprit.
 

tsandford

New member
Thank you very much for this thread. I just fixed my neighbor's 2013 GLI with this issue. They were about to have the compressor replaced and I was able to save them a lot of money by putting in a used alternator with properly operating freewheel pulley (original one had seized) and picked up a used compressor which I swapped the pulley over from. AC up and running again for $130.

If anyone has a sheared AC compressor pulley on a TSI, first thing you need to check is if the alternator pulley free spins in one direction, if not, that's the culprit.
Orangeman and Clockwise are my heroes. With 170,000 miles on my 2011 GTI, I first heard belt slippage at low idle. Thinking it was the belt and tensioner, I replaced both with only marginal improvement. Then saw a thread about the alternator pulley. It was indeed seized. While waiting for a new one, boom went the compressor pulley. I was just about to order a new compressor, expansion valve, condenser, dryer thinking the compressor seized. The compressor turned freely so I will proceed with just renewing the alternator pulley and compressor pulley. I had to use your creative idea to drill and split the hub of the compressor to get it off due to stripping the 7mm hold back and nothing left to grab on the hub due to breakage. Genius. And thanks again. Tim in NJ.

Added a few photos of the failed alternator pulley. It no longer functioned because the grease dried out preventing the needle bearings from engaging and disengaging the grooves on the hub. Needed the special removal tool set to get the pulley off. I did not have to take the alternator out of the car to change the pulley. Pulley was $38 on Amazon.

Also, 2 photos of the AC pulley and failed hub. made a tool from an old socket and 3 pieces of bolts so an impact driver could be used to easily take off the hub without using the 7mm shaft hold-back which easily strips. Tools can be purchased on Ebay. I bought one for $29 but then could not wait for shipping from China.
 

Attachments

  • alt pulley od.jpg
    alt pulley od.jpg
    1.1 MB · Views: 100
  • alt pulley hub.jpg
    alt pulley hub.jpg
    633.2 KB · Views: 100
  • compressor hub pulley.jpg
    compressor hub pulley.jpg
    1.5 MB · Views: 103
  • failed AC pulley and hub.jpg
    failed AC pulley and hub.jpg
    1.3 MB · Views: 106
Last edited:
Top