Automotive Air Conditioning Information Forum (Archives)

ordpete944 on Fri April 04, 2014 12:07 PM

Year: 2006
Make: VW
Model: GTI
Engine Size: 2.0T
Refrigerant Type: R-134a
Ambient Temp: 85
Pressure Low: 140
Pressure High: 150
Country of Origin: United States

Hello guys-

I have a 2006 VW GTI owned since new with 111,000 miles. The compressor and receiver dryer was replaced by the dealer under warranty at 45,000 miles about 5 years ago. It was operating fine when replaced, but the compressor was getting noisy.

About 2 years ago at 95,000 miles, the AC started to take longer and longer to start blowing cold when starting up the car. If the car was started and sat idling, it would take 10-15 minutes to start blowing cold. If you started driving immediately, it would blow cold when the engine got above 3000 rpm. Once the AC started blowing cold, it would blow ice cold regardless of engine or vehicle speed. So one morning when the car had sat overnight, I started the car, let the engine warm up for 30 seconds and then gently held the engine revs at 3000 rpms. After about 10-15 seconds, the AC started blowing cold. So I used this trick to get the air going faster since I live in Florida.

Over the last year it has been slowly taking longer and longer (1-2 minutes) of holding the revs at 3000 rpms to get the AC to start blowing cold.

Actions I have taken to try and fix:

I have a friend who does residential HVAC and he brought over his gauges. Hooked them up when the AC was blowing cold and the pressures were within spec for the car. I checked operation of the dual electric fans. Both worked. I cleaned the Condenser with a fin comb. Very little debris came out.

I tried the gauges again a few days ago. Disclaimer, I do not think these are 134a gauges. My friend says they would work, but I think they are just for home HVAC.

I hooked up the gauges before the car was started and the low side was pegged at 140 psi and the high side was 150 psi. I then started the car and let it idle with the AC on. The AC was blowing ambient air and the pressures did not move. I then gently revved the engine to 3000 rpms. After about 2 minutes, the AC started blowing cold, like a switch was flipped. The gauges then read low side 45psi and high side 210 psi.

I thought that maybe there might be some sort of blockage in the orifice tube or moisture in the receiver dryer that gets blown out after the engine reaches 3000 rpms and the compressor generates enough pressure to move it? Does this sound possible?

The compressors for these cars are notorious for locking up. Mine is not making noise. Someone suggested that maybe the system was slightly low on oil and the compressor was binding at the beginning.

I also found someone who had a similar problem for a slightly different model VW. He stated that he replaced the refrigerant control valve (integral A/C regulator valve (N280)) and that this fixed his issue.
link: http://volkswagenownersclub.com/vw/showthread.php/30118-MKV-A-C-Compressor-Control-Valve-Replacement

I am at a loss. I am mechanically inclined and will be buying a good set of 134a gauges and vacuum pump from harbor freight so try and fix this issue. I just don't want to start throwing parts at it. Any input would be greatly appreciated.

Thank you!

Pete

TRB on Fri April 04, 2014 2:17 PM

If the system has a full charge? Bet it is the control valve shot in the compressor. This model Sanden is known to have control valve issues.

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ordpete944 on Sat April 05, 2014 2:37 AM

Thank you for the input. Any idea where to buy the refrigerant control valve part? I am having zero luck finding it. I hear the dealer tries to get you to buy the entire compressor.

TRB on Sat April 05, 2014 6:46 PM

On this model compressor the control valve is internal and is not really a replaceable item.

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ordpete944 on Sun April 06, 2014 10:07 AM

Thank you so much for your input. I look forward to getting this finally fixed!

Pete

autoservicecoupons on Fri April 25, 2014 1:38 PM

ordpete944 did you get this fixed?