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Discussion Starter · #1 ·
Hey guys, well I replaced the expansion valve and got myself some new manifold gauges. The result? after replacing the valve and charging the system with only 16 oz of refrigerant the l/s pressure was 70-80 psi and the high side was barely over 100. Compressor? also today the little pain in my butt popped up a code p0172 and p1128. cleaned the maf with the dedicated cleaner and still there. o2 sensor? I'm literally going crazy with this stuff. I got this thing needing attention, my jetta needs the a.i.r solenoid and the timing chain is rattling. ugh. thanks in advance guys
 

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It is always best to pull a vacuum, then charge the system with 700 grams of freon. Exactly.
Are the fans working? The lack of air flow across the condenser will cause the pressure to rise.

Sent from AutoGuide.com App
 

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Discussion Starter · #3 ·
Oh yea everything is working as it should. Except no cold air. the compressor never cycles, just kicks on and stays on.
 

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A/c

I got the same problem except I don't know what my high side pressure is yet. The problem could be the refrigerant control valve inside the compressor, but if you gonna break the system open might as well replace the compressor, expansion valve, dryer and be done with. I might do that since the system is already over 10 years old anyhow.
 

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Discussion Starter · #5 ·
Yea I got a compressor on the way. Got the drier and a ew ex valve included in a kit from rock auto, but already got a new ex valve on it so... not doing that again. But as for the compressor and dryer should be done before noon saturday. I had a 98 jetta that had a bad one as well, and it exploded. took out the front air dam, radiator, fog light, busted a hole in the block and intake manifold, wasn't pretty. Glad I caught this one
 

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Discussion Starter · #6 ·
I got the same problem except I don't know what my high side pressure is yet. The problem could be the refrigerant control valve inside the compressor, but if you gonna break the system open might as well replace the compressor, expansion valve, dryer and be done with. I might do that since the system is already over 10 years old anyhow.
esse you can go to autozone or harbor freight and get a manifold set for less than 50. Really helps when trying to figure out problems
 

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info

Hey thanks for the info I will look into buying a set of gauges in the near future. I also read in another forum that your problem could also be the air mix door inside the HVAC Tunnel, the heater flap lever is known to come loose and blowing hot air into the evaporator and causing this problem, just FYI something to keep in mind.
 

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Discussion Starter · #9 ·
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FIXED!!! Thank you guys for your help! It was the compressor. I replaced it last night and charged the system up with 8 oz of ester oil and 16 ounces of refrigerant. Its AC is ice cold. Think I may evac my Jetta and rn some of that synthetic 134 stuff in it. This thing is way colder.
 

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FIXED!!! Thank you guys for your help! It was the compressor. I replaced it last night and charged the system up with 8 oz of ester oil and 16 ounces of refrigerant. Its AC is ice cold. Think I may evac my Jetta and rn some of that synthetic 134 stuff in it. This thing is way colder.
Hey congrats and it's good to see you got'er done. Did you put a brand new or rebuild compressor? Does our system take 8 ounces of oil? what are your pressure readings on the manifold gauges now as to compare to before when the compressor was bad? just trying to learn since I think mine compressor is also shot.
 

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Discussion Starter · #11 · (Edited)
Esse here is a pic of the gauges before the compressor install. I don't have a pic of what they were after but the low was 35-40 psi and the high was just a hair over 100. The compressor was from rock auto and the unit by itself is 186 plus shipping and the comp plus receiver/dryer and expansion valve is about 220. Believe its a reman unit but same as new pretty much. It did have oil in it as well, but I added just a little more to it, because you can't really overfill it (to an extent) as the oil circulate with the 134. It did not however come with new O rings. Little disappointed in that, and I HIGHLY recommend changing them. I bought 8 oz of ester 100 and an entire system O ring kit for 15 bucks at autozone. Also remember to coat the O rings in the ester oil. I've also used sylglide in the past but be careful not to get it in the system. They just need a little lube to keep from tearing. Don't know what the rules are for posting links but if it causes a problem I'll gladly remove it. RockAuto Parts Catalog

just click the drop downs until you find what you need. Watch out though because some of them are for Euro cars only. And one slight snag I had was the connector was the wrong shape so I just cut the connector off the old compressor and cut the new one as well and soldered them with heat shrink tubing. I wish i had thought to do a write up with pics, but any questions you have I'd be more than happy to help with. It's pretty straightforward r&r, but be warned your hands will be covered in scratches and scrapes. And I know some people do take them out from the bottom, but I chose to do it from the top. Even though it's slightly, and I mean very slightly, more work I just removed the alternator and had a load of room to get my tools in. The exp valve was a 5mm hex and 2 4mm hex bolts, the alternator and belt tensioner were 13mm bolts, and the compressor itself is 2 16mm bolts holding it to the block and 2 6mm hex bolts holding the lines in. That's it. Took me about 8 hours total but only 4 working because of the blazing heat.
 

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feedback

Hey thanks for the feedback. I just have one question though, what O-rings are you talking about? the line fittings that connect to the compressor? dryer? expansion valve? those fittings O-rings? BTW great pictures, thanks. I will try and do mine soon.
 

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Discussion Starter · #14 ·
Yep those are the exact O rings of which I speak. :)Even if you've never done this kind of work before (my experienceis fairly limited with AC) this is so easy. The only pain is having to have the 134 evacuated.
 

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compressor

hey I got very similar issues, my low side is 80psi and the high side is only 125, which is also low for that high side.......so looks like I'll be looking into changing the compressor in then near future. thanks for your help.
 

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Discussion Starter · #16 ·
Hey one thing I forgot to mention is an expansion valve and compressor are gonna look very similar on gauges. I would seriously recommend doing the valve first as its cheaper, much easier (3 bolts) and required with a new compressor anyway. But it sucks that you'll lose a full charge and have to recover and vacuum again (unless you own your own vac pump, and vent like some people do :thdown: ) but you'll fix it for 50 bucks if that's what it turns out to be instead of 220 or so. But if you have any questions just shoot me a message and i'll walk you through it
 

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A/c

Hey do you have the torque values for the hoses on the A/C system? where exactly is the expansion valve, you got a picture of this valve? is that the one by the firewall?
 

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Discussion Starter · #18 ·
I have no idea what the torque values are, but I was cursing trying to loosen them, so when I tightened them I tried to put them back to the same. Also the expansion valve is under a black plastic cover on the passenger side firewall. You'll see the 2 lines going in. Just pop the cover off and its a 5mm and 2 4mm hex bolts.
 
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