AC not working

B6/7 S4/RS4
#21

[quote=“koolade9,post:14,topic:5684”]
Never had an issue with the Audi, but drawing on recently rebuilding a nightmare of a 30yr old r12 system, some of the basics still apply here…

To the OP, just wanted to note that on the Audi, I do know that you have to add a specific weight of 134a vs. filling solely via low-side pressure reading…and you shouldn’t have to add oil each time you vac, only if you’re dis-assembling and cleaning out the system.

How long did they system sit flat? Did you replace the dryer before trying to vac/charge? That being said, are you able to get all the way to 30in of vac? If you’re getting low pressure codes, that’s certainly why it’s not kicking on, but when charging it, the system should kick on as soon as you hit the low-pressure threshold. That should’ve answered your ‘is the compressor working’ question…

yea im pretty sure it went to 30in of vaccum. he held it there for a while and never moved.

#22

ok so never mind this code. was just the outside temp sensor disconnected

#23

Looked with uv light last night. I see some splatter/dots of dye right at the compressor connections. Now the rad support is still on so that’s just what I saw peeping thru. That’s the only place I spotted dye throughout the whole system. I’m gonna remove the rad support today and get a better look. Can this compressor be bad and there’s a leak at the same damn time? Smh

#24

that would be annoying (if it’s both).

#25

If it was ever over-charged, bad things can happen… Keep in mind, just because there’s a leak at the compressor, doesn’t mean the compressor is bad…you could just need new seals there. Was the condenser removed or fiddled with while you had your bumper off?

#26

I dealt with it for about ~8 months when my compressor shit the bed and I was trying to diagnose some other stuff, but how do you not have issues with no defroster working up north. Without the AC defrost won’t do jack, unless you’re just cracking the windows at 0 degrees!

#27

because it just died on him a week ago he said

#28

My car is parked in a heated garage so not usually a problem. And normally, at freezing temps, it’s not fog that builds up, it’s ice, and I just crank the heat to full.

I think it would be a bigger problem living in places like Seattle/Vancouver where it’s quite humid and you need to defog the windshield with some kind of de-humidifier which is what AC does.

#29

He was responding to my comment about my own AC not having worked (and still not working) for 2 years :slight_smile:

#30

I’m preparing for that stupidly expensive new compressor

#31

^ah, makes more sense now, yea I was questioning about the defog part of it. When we did my install in Detroit Jay asked me to have my AC drained before the drive (AC lines removed for install and garage we used didn’t have the AC charge unit) so I drove up there with no AC. Not a big deal until I got close to Detroit and some snow and started fighting the windows fogging up lol. So I had heat on and windows cracked trying to find a happy middle ground. And summer tires didn’t like the snowy conditions either!

#32

Well it’s worked the last 4 years of ownership without a problem. Condenser was never removed. The most that had been done was the rad support was put into service position.

Remember the confusing thing is even with enough psi in the system the compressor still doesn’t kick on. That’s what has me baffled lol

#33

And all u good that have had bad compressors before what mileage did they go at?

#34

Around 75-80k miles or so I think.

#35

is the AC unit accessible reasonably easily? Or is it a nightmare?

is it expensive (part)?

If it’s manageable I’d be inclined to just replace it if the car has 7 years on it. Many of the 07 cars were put on the road in late 06/early07…so that’s 7 to 7.5 years ago.

#36

I’ve been told it’s middle of the road pain-wise. Not easy (for the compressor) but there’s worse.
The part itself isn’t cheap. Anywhere from $800 to $1100 CAD new.

#37

Pain in the ass doesn’t even do it justice. And yea my price 829. Dealer price 1200 Smfh

#38

Cheapest I’ve seem oem compressor is about $850/900.

I think you can get compressors from resellers for as low as $450/500, but couldn’t comment on their quality or which brand they were.

#39

wouldn’t the heat from all of your extra lights melt any snow/ice?

#40

[quote=“dtoys4.2,post:32,topic:5684”]
Okay, so it never even kicked on when you attempted to charge it… So it should look at the low pressure switch, which if the code for that comes and goes as you fill it, means that sensor should be working properly… Second thing it’ll look for is the temp probe working properly (assuming we have one on this car) but that shouldn’t be an issue in your case… That leaves the compressor relay…have you checked that yet? I’d hate to see you drop big $ for a compressor on a hunch without fully diagnosing the problem…