2004 Jetta TDI AC Issues

dgass

Member
Joined
May 13, 2017
Location
Tampa, FL
TDI
2004 Jetta
Here is the run down of all the issues and measurements I have gathered
-2004 Jetta
-Big fan died and noticed this because I started trouble shooting AC not blow cold
-Discovered big fan was seized and I replaced
-Tried to start fan and discovered fan controller was dead so I replaced that also
-Fans now work fine but AC is even blowing warmer
-Measured pressures
-System off 110 PSI both high and low
-System on low goes down to 50 and drifts back up to 65, high never goes above 150 and ambient temp is 80 degrees F
-Clutch is engaging but low rumbling noise coming from the compressor

I suspect the compressor is no good maybe due to running without proper cooling. Thoughts?
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
100% your compressor is fubar.
If you’re going to do this job yourself, please does it right?

Start with getting a NEW OEM compressor, dryer, ac o'ring pack, expansion valve, and dryer temp sensor. Also get an AC flush chemical, a tank of nitrogen, a few ounces of PAG oil, and a few tanks of 134a with no additives what so ever, no A+ synthetic crap, just 134a, a scale, seems like you have a set of gauges, vacuum pump, and the other various things you need.

Take all the hoses apart, change all your orings, and parts, save the dryer for last, DO NOT INSTALL the dryer yet, this is the last step. junk the old AC compressor, drain the NEW one, and verify the pag oil added is exactly what is called for, not even a half ounce more or less. This is a big step everyone skips. Flush out all your lines and cores with chemical flush, you can use acetone but its old school and not very good compared to other chemicals. Purge all your lines with NITROGEN, not compressed air, now assemble everything save for your dryer, now purge again with nitrogen and crank the valve down a bit so it’s still flowing but just a tiny bit, now hook up your dryer filter one port at a time, so that the plastic plugs are taken out once then hooked up, then the other. You want to minimize the exposure to the air for the dryer as much as possible. Now that it’s all back together, pull a vacuum, if you don’t have the $$$ to go for a micrometer to check vacuum, the cheap ones are junk and don’t work, if you did not spend $400 on one, its junk and can’t be trusted. Just pull a vacuum for 1 hour and shut the valves on the vac port. If within 12 hours it does not loss vacuum, your good. Now crack open the nitrogen tank and bring the system up to 200 PSI and let it rest for an hour, if you stay at that pressure, you are good to move on, Pull another vacuum for 1 hour min. Now get the scale, hook up your tanks, making sure to p[all a vacuum on the charge line and all that, now zero the scale, pierce the tank and bring on the 134a, go to spec on how much by weight within +/- 5% is fine. Now start it up to help it get sucked in on the low side, never tip the tank on its side, only upright and SLOW, if you get liquid in on the low side, you will destroy the compressor within seconds of running. You can put it in a tank of hot water, just keep track of your scale and write that all down so you can keep track of it. go to spec and check your high and low, 30is low side, whatever your 2004 calls for the high, but you need to do a supper cool supper heat function to measure the lines, ambient air and what not to reliably go off pressures alone. DO NOT OVER CHARGE by weight.
Good luck, btw if you do this any other way, it’s a guarantee to fail within a few years or sooner. There is only 1 way to do AC right, and that’s this way. Trust me, I do HVAC.
 
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