AC Freezing up, and driving me crazy.

bobbytdi

Member
Joined
Sep 2, 2013
Location
FairChilds TX
TDI
2014 jetta tdi
Hi all! I bought my 2014 jetta for a vw dealer about 2 years ago. A new ac compressor was put on the car a week before I bought it according to the records. I noticed the day i got it home it was iced up. . I bled off a bunch of Freon thinking it was over charged, and charged it to 10 degree super-heat, and it seemed better.. Later I blew the Freon, pulled a vacuum and recharged by weighing in the Freon. Iced up again after running for 1 minute. Replaced TXV, pulled vacuum and recharged iced up again in 1 minute. Replaced the High side pressure switch thingy, freezes up in 1 min. Yes, both coils are clean, as is the air filter, the blower is running. I am the owner of a ac business. I feel like the compressor is not unloading. Compresser does unload 100% if I unplug the high pressure switch thingy. AC blows ice cold and will burn your face its so cold, but it makes ice..lol What am I missing here>? Please help! THANKS!
 

bobbytdi

Member
Joined
Sep 2, 2013
Location
FairChilds TX
TDI
2014 jetta tdi
So, ive been under the impression the compressor was a variable displacement compressor, Its NOT! I hooked the high side pressure control thing up to a bottle of nitorgen and ran the pressure from 0 to 150 psi. What I found was 0-19.5 compressor runs unloaded, 19.5-140 psi, compressor runs loaded. No change in suction pressure. Turns out ice problem was due to being low on freon. This time i purged my gauges with freon to account for my hoses, zeroed my scale, and weighed freon in. On fan speed #1-3, 5.8 superheat, and 2.5 subcooling. Most importatly no ice, even on fan speed 1. Before it was 0 superheat. It was a you know what trying to get my temp clamps on the lines, and im fully deleted. Hope this helps someone else because I didnt realize being the system is so small and being just a tad low would make this big of a difference but it does!
 
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