A/C issue

[tracy.kordis]

Hello. When I first start my car, the A/C only blows hot air for about the first 5 - 10 miles, then it will blow cold, but not super cold air. I've had the freon checked and it's good.
It will only work on certain settings, though.
2006 Jetta TDI

 

[Windex]

How do you know that the freon is "good" how was it checked?

 

[Mongler98]

lol it was checked? by whom? acid test? Low and High side pressures? or just some rando (or you) with a low side only charge scam kit?
Your car has a OBD2 port. your car also can give you data on the AC system and faults. start there. VCDS is the tool of choice. proper rosstech cable, no ebay shenanigans please.
There is also a thread called "check your condenser fans now" check it out.
typically most issues are either electricall or no charge due to damage. acid test $8 and a pressure gauge are only necessary AFTER you diagnose the electrical side of it.
AC threads here are massive. i suggest you do a search in your cars thread area. read up.
I highly suggest you take it to one of our TDI trusted mechanics here on page 101 right at the top.
that or spend $400 to $500 on proper tools and materials to diagnose and service. Its not complicated but if you do not follow steps most leave out like using nitrogen and micron vac gauge... you are doomed to fail.

 

[tracy.kordis]

How do you know that the freon is "good" how was it checked?

Forgive me for my lack of knowledge of verbiage, but my cousin who is a diesel mechanic, had some sort of contraption that had 2 gauges on it and hooked into 2 different "ports." It wasn't blowing cold air at all, which is why i asked him to check it. It actually had too much freon in it and had to bleed some out. It started blowing cold air after that, but the delay is still there.

 

[tracy.kordis]

lol it was checked? by whom? acid test? Low and High side pressures? or just some rando (or you) with a low side only charge scam kit?
Your car has a OBD2 port. your car also can give you data on the AC system and faults. start there. VCDS is the tool of choice. proper rosstech cable, no ebay shenanigans please.
There is also a thread called "check your condenser fans now" check it out.
typically most issues are either electricall or no charge due to damage. acid test $8 and a pressure gauge are only necessary AFTER you diagnose the electrical side of it.
AC threads here are massive. i suggest you do a search in your cars thread area. read up.
I highly suggest you take it to one of our TDI trusted mechanics here on page 101 right at the top.
that or spend $400 to $500 on proper tools and materials to diagnose and service. Its not complicated but if you do not follow steps most leave out like using nitrogen and micron vac gauge... you are doomed to fail.

Forgive me for my lack of knowledge of verbiage, but my cousin who is a diesel mechanic, had some sort of contraption that had 2 gauges on it and hooked into 2 different "ports." It wasn't blowing cold air at all, which is why i asked him to check it. It actually had too much freon in it and had to bleed some out. It started blowing cold air after that, but the delay is still there.
I appreciate your thorough answer, and the information and time. Thank you!

 

[Mongler98]

Forgive me for my lack of knowledge of verbiage, but my cousin who is a diesel mechanic, had some sort of contraption that had 2 gauges on it and hooked into 2 different "ports." It wasn't blowing cold air at all, which is why i asked him to check it. It actually had too much freon in it and had to bleed some out. It started blowing cold air after that, but the delay is still there.
I appreciate your thorough answer, and the information and time. Thank you!

Do not let your bro or cousin or whoever near your car again.
The system worked before right?
It is impossible to suddenly have too much refrigerant in the system.
He used what's called a manifold gauge set.
When the car is running and the compressor is working and its blowing cold you need to see specific pressures.
By the sounds of it the compressor could be worn a bit or something is not doing its job enough like a cabin filter or clogged evaporator or the fans on the condencer not working properly. These and many other things can make it look like there is too high of a pressure for the ambient temp air going over the evaporator.
Please. Like I said either take it to one of our professionals or buy the tools and risk doing it yourself and I encourage you to just take it to a proper mechanic. Not your bros

 

[tracy.kordis]

It was NOT working before my cousin checked it. It is back to working intermittently (like it was before) after he released some freon. The car and the AC were both running when he checked it. He has diesel trucks that he has had issues with as well, so he knew what he was doing. He IS a mechanic, but doesn't have enough time to really dig into the main issue on this car . I appreciate both your time and knowledge, but not your condescension. I was simply trying to gain some insight, as I know VWs are very specific animals, and wanted to ensure that I had some sort of information before I take it to a mechanic.

 

[Mongler98]

Well you said bro. Not mechanic.
Be specific. We cant read your minds.

 

[Vince Waldon]

Hi Tracy, welcome to the forums, hopefully you're able to ignore our resident grump.

You're wise to double-check, but in this case the VW A/C system is a pretty standard set-up and any competent shop equiped with a proper A/C service machine should be able to diagnose and empty/vac test/recharge as required.

The "empty" part is important (and something you can ask a potential shop to confirm they know what they are doing); these systems are filled by weight and so the only way to properly charge them is to completely empty them first and then re-fill with a known weight of refrigerant. If a shop tells you they will check the system by simply "topping up the charge" consider moving on.

 

[Mongler98]

technically they are filled by weight, then adjusted by pressure. unless the pump is new... it may not run optimally for the weight.
the ONLY reason to dump a charge is knowing something is wrong with a component. It can be reclaimed and added back into the system.
you need to add oil back if you dump a charge but there is a chart for that.
dumping a charge just to weight it back in is the most ill advised nonsense i have ever heard.
call me a grump all you like but thats strait up ignorance to dump his charge.
There is this thing... pressure... you know, comes from having a specific amount of stuff in a thing...
OP clearly wants to DIY this and there is plenty of good info out there and TONS OF BAD info. like dumping a charge to weight it back in for no reason other than ignorance of pressures.

 

[Mongler98]

Its also 100% impossible to know the charge and thus the need to dump it if the compressor isn't running. OP's mechanic is just another goob who hooked up some gauges to a non running car, dumped some now it runs.
there are metering valves in these compressors that divert freon when not needed, expansion valves, and what not that get clogged up by a failing system that can mimic high pressures on a RUNNING pump. you need to know high and low side to determine HOW much refrigerant to RECLAIM.
you do know its a federal violation for a mechanic to knowingly discharge HFC's into the atmosphere, THis is not diminimus loss.
OP never answered any questions here. We need to know High side, low side pressures on an operating pump. we also need to know if this was how OP got the car.... or why it was too full.
we have nearly no info to go off of at all. this thread is pointless with out info.

 

[hskrdu]

Most of my saved threads for AC operation are for the MkIV not MkV, but a search will bring you more good info. If nothing else, reading these will allow you a better idea of the system, and maybe others can link MkV AC threads.

Check your radiator/condenser fan operation NOW

Mk IV Manual AC electrical & cooling fan troubleshooting and repair Now is the time of the year to check that your pair of electric fans that provide cooling for both the radiator and air conditioner condensor are functioning. Do not needlessly age your Air Conditioning compressor by running it...

forums.tdiclub.com

https://pics.tdiclub.com/data/517/A4_Air_Conditioning_Troubleshooting_Rev_7.pdf

Here's a MkV thread, but there are more out there:

2006 jetta tdi no a/c

Hi wondering if anyone has break down of the fuses under the hood and under drivers side with the relay break down for the air conditioning. I was also wondering about a fan control module if anyone has a pic or where it is would be appreciated. I have power going to my fans but they dont come...

forums.tdiclub.com

 

[nicklockard]

Hello. When I first start my car, the A/C only blows hot air for about the first 5 - 10 miles, then it will blow cold, but not super cold air. I've had the freon checked and it's good.
It will only work on certain settings, though.
2006 Jetta TDI

Welcome to the club; sorry you've been Mongled already. Did you have a shop check out the system yet? What setting work?

 

[1854sailor]

Contrary to Mongler's suggestion, you do not need a TDI guru to diagnose an A/C issue. Any good A/C shop that is familiar with the VW system should be able to get you working.

 

[Mongler98]

Contrary to Mongler's suggestion, you do not need a TDI guru to diagnose an A/C issue. Any good A/C shop that is familiar with the VW system should be able to get you working.

Where did I say you did?
I said I highly suggest one of our trusted mechanics on our list.... because we trust them....
Dont you agree? Or are you suggesting OP not trust our trusted list?

 

[oilhammer]

Sounds like a typical bad RCV to me.

Mongled, LMAO.... that's gold!

 

[Shoveltrev]

this ac stuff makes me laugh . a rcv system with expansion valve will attemp to maintain the quote unquote proper pressures all the way down to 4 ounces of freon , with 2 variable orifices competing you absolutely must charge by weight not by pressure. a fixed displacement compressor in a orifice tube system can be charged by pressure. again technology gets away from some of us .

 

[Mongler98]

this ac stuff makes me laugh . a rcv system with expansion valve will attemp to maintain the quote unquote proper pressures all the way down to 4 ounces of freon ,

yes, 100% agree with ONLY that part, however, there is this supper cool supper heat method, and it works just fine for these systems. i guess im wrong... been charging these systems based on low side till the high side starts to clime to match the low side via super heat super cool temp readings on the low and high side lines. how i was thought the "wrong way" still works fine. don't care what pressures are if the supercool saturation says otherwise. volume of refrigerent will dictate the temperatures.

 

[AndyBees]

Well, this one certainly has had a good stirring ..........

I've read and re-read the Original Posters first four Posts. I'm at a total loss as to where he used the word bro. Maybe I've missed it! Also, I do not see an indication he "edited" any of his posts

I've serviced the AC systems on my formerly owned 2000 Jetta as well as my 2003 Jetta and others (successfully, I might add) ..... always by use of Manifold Gauges. Low side pressure of 40-50 PSI and above 200 PSI on the high-side, preferably about 250 psi, depending on ambient temp is what I try to achieve. Also, these numbers worked well on my 95 Chevy Blazer when I had to install a new compressor.

I had to sort thru a lot of stuff with the AC system in my 84 Vanagon ........... ALH engine and Jetta AC Compressor ....... with an Expansion Valve. I had to remove the RCV for it to work properly.

Tracy Kordis, welcome to the Club and don't be intimidated by what appears to be a few off the cuff remarks. These guys like details and more details.

 

[DivineChaos]

Sounds like a typical bad RCV to me.

Mongled, LMAO.... that's gold!

Why do so many totally forget that. Acid test immediately. Smh. I just replaced my rcv and condenser because the fins were half gone. Ac works great now.

 

[Mongler98]

Why do so many totally forget that. Acid test immediately. Smh. I just replaced my rcv and condenser because the fins were half gone. Ac works great now.

exactly, literally the 3rd ting i questioned in post #3.... and i ask every time.

 

[Abacus]

Well, this one certainly has had a good stirring ..........

I've read and re-read the Original Posters first four Posts. I'm at a total loss as to where he used the word bro. Maybe I've missed it! Also, I do not see an indication he "edited" any of his posts

Tracy Kordis, welcome to the Club and don't be intimidated by what appears to be a few off the cuff remarks. These guys like details and more details.

The OP didn’t, Mongled did (that is a fitting moniker). The op clearly stated (twice)

…but my cousin who is a diesel mechanic…

that his cousin who is a diesel mechanic did. Maybe in Monglers mind that means “bro” but not in any normal sense of the English language.

These systems are not voodoo but do take some knowledge to fix properly. If your cousin is a diesel mechanic that’s good enough for me. No need to be a guru or some all-special, all-knowing expert that passes the Mongled test because half of what he says you can ignore anyway, along with ALL of his condescension. Now mechanics on the board like Oilhammer, Windex, Matt Phelan (who didn’t chime in), and many others, I would absolutely listen to and heed their advice since you can believe it.

But welcome to the board, Traci Kordis, and try not to let one lone inconsequential person dictate your opinion of us here or the knowledge offered.

 

[oilhammer]

To the OP:

On your car, you also need to be sure BOTH fans work. And on the BRM (and all A5 cars, no matter the engine, for that matter), the fans require some refrigerant pressure to kick on, even low speed. So if there is NO pressure being created, no matter the reason, the fans will not come on. The system can have a full charge, but the RCV in the compressor is so bad or so weak that it just cannot let the compressor make enough pressure to make the fans work, and of course the system won't remove heat like it should.

With a suitable scan tool, you can go in and watch the A/C command and pressure value, although I do not often even spend the time with that anymore. I keep a stack of RCVs on the shelf. Most Sanden compressors (which is most of these cars) use the same clip-in RCV. They are pretty easy to change. I evacuate the system, look at the amount I took out, if it shows close (2/3 or more) of a full charge, I swap the RCV and recharge the system, confirm the fans kick on, and that the system cools. I also verify the cabin filter condition if it is not a car I regularly see.

Fairly simple process. It is just into July now, and I have already replaced probably 20 RCVs on various VAG products so far this year.