A/C Issue

[stefcio007]

My AC didn't work very well when I bought the car. Re-gassing fixed it and it was ice cold...except now it's not anymore.
While driving I do hear the kind of gas flowing sound and it gets a little cold but not much.
I assume it's a leak...is there anywhere where they will fix a leak?
Bit annoyed since I got this re-gassed last year and it cost me $150...thought that would include a basic check for leaks and don't really feel like I should re-gas every year especially if there's a leak.
MFA showed 39 degrees C outside today.

What's the first step to finding a leak? Should I just find someone who will be able to find and fix it for me? How much?
Thanks

[milan12]

I am going to keep an eye on this thread because my cabs aircon has a similar problem.

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[BurgundyMk3]

Is there any foam stuck inside your vents?

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[stefcio007]

Is there any foam stuck inside your vents?

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A few weeks ago took out heaps.
I have really good airflow everywhere.

So coming back home tonight it was 32°C on the MAF.
AC appeared to be doing a decent job.

So maybe the AC ambient temp sensor was too hot and it was cutting out sporadically?

[BurgundyMk3]

Is not about the airflow. That foam was covering a mixer flap which is used in the heating/cooling system. So basically because all that foam has come off the flap. The cold air coming in mixes with the hot air temps from the coolant hoses from the heating section. Therefore your getting warmer vent temps

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[stefcio007]

Is not about the airflow. That foam was covering a mixer flap which is used in the heating/cooling system. So basically because all that foam has come off the flap. The cold air coming in mixes with the hot air temps from the coolant hoses from the heating section. Therefore your getting warmer vent temps

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I wasn't aware of that. I'm fairly sure all the foam has come out, but if some leftover rattled about and caused the issue that you described then it could be the case. I always run it with the "circulate air" switch on though, as with it off, the air becomes warmer.

[stefcio007]

Did an airport run today and everything appears normal. Maybe it was because I hadn't used it for a long time or it doesn't work as well if you're not moving and stuck in traffic.

[mattross]

IF AC LEAK: When they re gassed they usually put a dye in to track leaks - need a UV light to see. You should also test the high low pressure switch under the front bumper. Other possible problem in the A/C fan switch in the radiator - can also be tested. This might be the reason it started working when not in traffic (air flow cooled it down)

FOAM IN VENTS - its heater core box. The air vents hot/cold flap has a foam covering that degrades. If so the air flows past the heater core and cold AC air warms up and comes out warm. Its a massive fix to repair this - have to pull the whole dash out to get too. I've done it, it wasn't fun.

My alternative ghetto repair on this is - under the hood, find the two water lines to the heater core in the firewall and add two closable valves and in summer, close them off you dont need them in the heat, in winter open them up.

Remember, VW recommend you run the A/C once a week for oil/lubrication of seals

[stefcio007]

IF AC LEAK: When they re gassed they usually put a dye in to track leaks - need a UV light to see. You should also test the high low pressure switch under the front bumper. Other possible problem in the A/C fan switch in the radiator - can also be tested. This might be the reason it started working when not in traffic (air flow cooled it down)

FOAM IN VENTS - its heater core box. The air vents hot/cold flap has a foam covering that degrades. If so the air flows past the heater core and cold AC air warms up and comes out warm. Its a massive fix to repair this - have to pull the whole dash out to get too. I've done it, it wasn't fun.

My alternative ghetto repair on this is - under the hood, find the two water lines to the heater core in the firewall and add two closable valves and in summer, close them off you dont need them in the heat, in winter open them up.

Remember, VW recommend you run the A/C once a week for oil/lubrication of seals

Pretty sure it's the foam in the vents as you say.
I turned off all AC, fan, temp all the way to the left and I had hold air flowing through the vents not pleasant.
The closable valves seems like a good option. As I can see there are just two hose clamps there so easy to take off.
Just a question. Is there any fluid in those lines? I assume there is.

[mattross]

Yes, there is water in the lines. The Heater core is a small radiator in the back of the dash which takes engine radiator water in and uses the coolant water to radiate (thru a radiator/heat exchanger) and heat the cabin via directing air accross it.

A simple test here - disconnect these two lines and do your test again, this will definately indicate whether the flap is gone.

There is a few forum topics on this, usually under heater core... a few below
Change Heater Core
Heater Core Bypass (Mk3 VR6)