Delayed Air Conditioning
- Thread starter robrichtx
- Start date
Hope this is posting! Its my first time posting from my cell phone...
Just picked up the car from vw autoworks and they said there was a bad wire in the harness. They also had to replace the ac relay. They said that is why the ac never worked untill the car got warmed up. The fans would kick on when the car was warm and there for the ac would start getting cold. I hope this is going to fix it! Only time will tell.... I will know in the morning after the car sets over night. I will post when I get to work tomorrow.....
Lonnie
Just picked up the car from vw autoworks and they said there was a bad wire in the harness. They also had to replace the ac relay. They said that is why the ac never worked untill the car got warmed up. The fans would kick on when the car was warm and there for the ac would start getting cold. I hope this is going to fix it! Only time will tell.... I will know in the morning after the car sets over night. I will post when I get to work tomorrow.....
Lonnie
Well never mind! The ac took 11 min. to come on this morning so I guess I just got ripped $380.00 for nothing..... When will this ever enddddd!
Lonnie
pawel
Veteran Member
- Joined
- Apr 19, 2008
- Location
- Naugatuck, CT
- TDI
- '09 TDI 6 MT, Platinum Gray Metallic, Anthracite Interior
Dan,
Is that what might be happening in my case?
DanG144
Top Post Dawg
On your vehicle, actual current is not reported to the ECM.
So I would put a clamp on DC ammeter and verify the current is what it should be. Once the current reaches .820 amps, that is all the control system can do.
On yours, Pawel, I would suspect that the fans are not providing adequate cooling (though they are running), which is impacting the efficiency of the system.
I would also check the actual current being supplied to the RCV, Pawel.
So I would put a clamp on DC ammeter and verify the current is what it should be. Once the current reaches .820 amps, that is all the control system can do.
On yours, Pawel, I would suspect that the fans are not providing adequate cooling (though they are running), which is impacting the efficiency of the system.
I would also check the actual current being supplied to the RCV, Pawel.
Couldn't he spray the condenser with water to verify this?
DanG144
Top Post Dawg
He can. He could also use a strobotach to determine if the reported speed to the ECU/HVAC module is correct. His reported speed is only about half of what is requested.
What I REALLY want to know is for the guys with delayed AC (Pawel's is NOT delayed, just poor), what is the actual measured current to the RCV during the period that the compressor should be loading, but is not loading. I would like to see an independent measurement with an inline or clamp on ammeter, during that period, with the VCDS log of pressure, current, fan speed, and permissive signal for the same period.
What I REALLY want to know is for the guys with delayed AC (Pawel's is NOT delayed, just poor), what is the actual measured current to the RCV during the period that the compressor should be loading, but is not loading. I would like to see an independent measurement with an inline or clamp on ammeter, during that period, with the VCDS log of pressure, current, fan speed, and permissive signal for the same period.
pawel
Veteran Member
- Joined
- Apr 19, 2008
- Location
- Naugatuck, CT
- TDI
- '09 TDI 6 MT, Platinum Gray Metallic, Anthracite Interior
Dan,
I presume that in order to check the supplied current to the Refrigerant Control Valve (RCV), I should unplug the connector going to it and read out the current while the AC system is on?
And where is RCV located? I hope that I can access it from the top...
P.S. Dan, did you get my scan data?
DanG144
Top Post Dawg
I have reviewed your scan data.Dan,
I presume that in order to check the supplied current to the Refrigerant Control Valve (RCV), I should unplug the connector going to it and read out the current while the AC system is on?
And where is RCV located? I hope that I can access it from the top...
P.S. Dan, did you get my scan data?
To check current flow you either have to clamp an ammeter around the line (a single wire - not a pair) (and clamp on DC ammeters are not really common) or you have to insert your ammeter into the current flow path. If you lift a wire, you stop current flow. So for an in-line meter you lift a wire, hook one end of your ammeter to the plug, the other end to the jack, such that current can still flow to the device.
The RCV is the only electrical device on your compresssor. So the two wires that run to the back of the compressor are the ones in question.
delzeit
Member
Hey Dan - Looks like I'm back in the mix. If you recall, about a year ago I had the same delay issue. This moved to the ac working intermittently. I originally replaced the pressure switch to no avail. Against my better judgment, I took it to the dealer to have diagnosed. They said it was the compressor and wanted $1200 to replace. I politely declined. I ordered a compressor replacement kit and had my mechanic install. He test drove and all worked well. When he got in again, it would not work at all. We suspected a bad compressor. After he talked at length with a tech that had great knowledge of these systems, I got the compressor replaced under warranty. The mechanic said the second replacement looked way better quality wise than the first. Well it has been a month since the second unit was installed. It had been working perfectly. Made a stop while on vacation. When I started the car again, no ac. Have not had it since. Working on my next move. May be a control unit issue. Perhaps it is sending constant current to the compressor instead of the pulse mode needed to operate and burning up the electronics. Too bad VW didn't stick to the technology that all other manufacturers have used for years. Makes for difficult diagnosis. I still have the original Sanden compressor. May tear down to see what makes it tick. Will be following this post to see what you all come up with.
Just took the car back to the dealer since no one can find anything wrong with it. They called and said its the compressor again! They are going to see if VW will warranty it since they just replaced it last year. Hope to hear something today about it...
Lonnie
Lonnie
DanG144
Top Post Dawg
Lonnie,
Please ask your dealer if you can have the compressor. I would love to get my hands on it.
Dan
Please ask your dealer if you can have the compressor. I would love to get my hands on it.
Dan
Dan,
I picked the car up today and we will see what happens in the morning because thats when it does it.... I asked about the compressor but they said no because the warranty paid for it. If I would have had to pay for it you would have been getting my old one if you know what I mean. They told me that they think that the techs are not doing the proper break in on the compressors when they are installing them. They gave me a 12k mile 12 month warranty on the compressor. I will post in a few hrs and let you know what happens on my way to work in the morning.
Lonnie
DanG144
Top Post Dawg
If you learn what a "proper break in" is on an AC compressor, please share it with me.
I have no clue how to break in a compressor. I just add the right amount of oil and freon and put it in service. (I am not a professional mechanic or AC system service tech.)
I have no clue how to break in a compressor. I just add the right amount of oil and freon and put it in service. (I am not a professional mechanic or AC system service tech.)
Well its funny now because the A/C was cold before I even pulled out the garage this morning! Outside temp was around 80* this morning and it was cold before even leaving the garage... Its like night and day now how fast it gets cold. I can't wait to go home after work today and have Cold air and not have to wait 5-10 min for it to get cold.
Dan,
The only thing that they said was something like spinning the compressor 15 times and then when you install it there is a step by step process that they go by. It had something to do with letting the car idle for ? min without the A/C on and then turning the A/C on 1 for ? min. It was something like that but I will see if I can get something from them that says exactly what has to be done if they will!
Lonnie
Dan,
The only thing that they said was something like spinning the compressor 15 times and then when you install it there is a step by step process that they go by. It had something to do with letting the car idle for ? min without the A/C on and then turning the A/C on 1 for ? min. It was something like that but I will see if I can get something from them that says exactly what has to be done if they will!
Lonnie
DanG144
Top Post Dawg
Don,
I was not aware that the control signal to the compressor was a pulse. I thought it was a DC current, that would be constant at 0.820 ma when asking for full displacement. I will be interested to measure this and know for sure.
The fans do use pulse width modulation to control the fan speed.
The pressure switch does send out a pulse width modulation signal that is proportional to pressure.
The electric Refrigeration Control Valve (RCV) has been used for years, I would say at least 10 years. That being said, it seems the electric clutch and directly pressure controlled RCV combination is more reliable.
swoboda
New member
ps
never saw any resolution to this problem. having the same problem with 2006 jetta tdi. anybody have any luck with a solution?
never saw any resolution to this problem. having the same problem with 2006 jetta tdi. anybody have any luck with a solution?
Will love to hear a resolution, Mine is still doing it and it is a pain in the @$$. It almost seems like the computer holds the AC until the engine is warm or something. my next test would be to stop using the AC for a while then turn it on once the car is warm and see if there's a delay then.
How can VW get this wrong!
How can VW get this wrong!
I had the same problem and got it fixed under warranty recently. Not sure where the exact problem was because they nearly changed out the whole system (three pages on the service receipt). They said the systems was clogged by small metal flakes which restricted the flow of freon.
thesearcherman
Veteran Member
I am just trying to help, maybe save you some time and money, so don't think I am out to get you. I have been reading the threads and, as complex as the Germans made the VW A/C operation, I just do not think self repair is the way to go. You need so much equipment to do the tests/repairs properly. Recovery equip., vacuum pump, nitrogen, leak detector, gauges, meters, books. What good does it do to have a set of gauges if you can not interpet the readings? For instance, the low side, (suction pressure), depends on quite a few things, high side pressure, evap. fan speed, evap entering air temp, refrigerant level, and in autos, engine rpm. An example would be with R134, if you have about 50 psig, (low side), then you have about a 55 deg. saturted evap temp., what this means is that if you have say 80 deg. air going into the evap, depending on evap. fan speed, you would have maybe 65 deg air coming out, and you will not be happy, as it will not cool, as you cannot cool the car with 65 deg. air on an 80 deg. day. These figures are approximates. If you insist on working on your A/C, then I would advise you to read alot of books, go to nite school, and remember you are dealing with high pressures, and could easily loose an eye or even worse. I went to nite school for 3 yrs. just for A/C. Sorry I cannot tell you what you want to hear. Just trying to help.
Thanks for the advice, Not sure to whom this was directed but in my case the car is still under warranty, I want to know what the problem is to compare it to what the dealer says.
In the case the car had been out of warranty and people where sure that say "the compressor" was the faulty part, I have no problem swapping it myself. I have access to ASE mechanics with all the equipment and that can provide advice. In 1998 we swapped an evaporator on a 1992 celica, and did the conversion to R134. nothing fancy. Car still cools after 12 years, not a single issue with the AC since. (maybe I was lucky
)thesearcherman
Veteran Member
Well, was meant for everybody. If someone says their compressor is the cause of delayed cooling, but it cools fine after delay, would someone please tell me technically how this is possible? High priced items mean more profit, the money is made in parts, not labor. A successful "hosing" means you do not know you have been "hosed", you cannot beat someone at their own game.
Working on a 92 Toy is not even close to a newer German car, how much diagnostic ability does it take on a leaking evap?
Working on a 92 Toy is not even close to a newer German car, how much diagnostic ability does it take on a leaking evap?
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Alright, at some point one would expect common sense to kick in. So odviously just saying that the compressor is at fault is not enough, Say there was an internal valve on the compressor that is sticking, once the valve opens the AC could function as expected. This is not rocket science, I'm sorry, I do not mean to say that your 3 years of school or your experience is something anyone can do. I agreed with your previous post, and thanked you for it. but also understand than you are dealing with different technical levels, do not assume people don't know what they are talking about, I don't know what your comment on the Toyota was all about.
Took the car to another dealer a few weeks ago and they replaced the compressor, (I have pictures of the before and after PNs if anyone is interested)
I was able to test the new compressor twice so far, basically the same scenario that caused it to fail before, parked car on a Friday, never used the car the next day, then used the car sometime Sunday. Turn the car on and start the AC. both on pretty hot South Florida summer days, both times AC started cooling within 10 seconds or so, Not full blasting cold, but definitely cooler than ambient until after some more seconds nice and cold.
Before one would get no cooling at all for like a minute or 2 or so miles of driving. Now car moves a couple of yards and I feel it cooling. SO far so good and it seems to confirm that the compressors are at fault. There seems to be no Compressor clutch on these compressors, they run continuously and the on/off button on the dash probably triggers the internal valve to open and close. so it seems this valve tends to get stuck on some compressors. This is what I was told, but seems probable.
I was able to test the new compressor twice so far, basically the same scenario that caused it to fail before, parked car on a Friday, never used the car the next day, then used the car sometime Sunday. Turn the car on and start the AC. both on pretty hot South Florida summer days, both times AC started cooling within 10 seconds or so, Not full blasting cold, but definitely cooler than ambient until after some more seconds nice and cold.
Before one would get no cooling at all for like a minute or 2 or so miles of driving. Now car moves a couple of yards and I feel it cooling. SO far so good and it seems to confirm that the compressors are at fault. There seems to be no Compressor clutch on these compressors, they run continuously and the on/off button on the dash probably triggers the internal valve to open and close. so it seems this valve tends to get stuck on some compressors. This is what I was told, but seems probable.
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DanG144
Top Post Dawg
Yes, the fault seems to be in the control system, but it could be the Refrigerant Control Valve (RCV), or the piston that it ports refrigerant to, or the wobble plate sticking - any of the three.
I have a 07 Jetta 2.0 TDI with similar problem.
I know many Golf (Rabbit) owner have encounter the same problem.
Instead of replacing the compressor, they have replaced the follow part and said it worked (click to view larger photo):
The above part was removed from the compressor:
If everything else is in good condition, this *should* fix the problem.
I have just got it replaced 2 days ago. Therefore, I can't say for sure at this moment.
Sadly, I don't know the name of the part in English. It might be Refrigerant Control Valve.
I know many Golf (Rabbit) owner have encounter the same problem.
Instead of replacing the compressor, they have replaced the follow part and said it worked (click to view larger photo):
The above part was removed from the compressor:
If everything else is in good condition, this *should* fix the problem.
I have just got it replaced 2 days ago. Therefore, I can't say for sure at this moment.
Sadly, I don't know the name of the part in English. It might be Refrigerant Control Valve.
DanG144
Top Post Dawg
That is the RCV or Refrigerant Control Valve. I hope it fixes your problem. Please let us know after a week or two.
Newgene
Veteran Member
This is one interesting thread. The wife's 2007 2.5 has been having annoying delay for over a year now. I believe it cuts in and out sometimes, but it's probably only noticed when it is really hot (go figure). Now, my 2009 does the same thing. It always comes on, but it now has about a 1 minute delay on start, and it seems to stop blowing cold when I slow down and come to a stop from highway speeds. It's been doing it for a few months, and in the back of my mind I thought it was a Passat type relay issue.
It'll be interesting to follow this one and see where it goes.
It'll be interesting to follow this one and see where it goes.
DanG144
Top Post Dawg
A one minute delay is probably about normal, not a malfunction.
From what you describe on your 2009, you need to verify that your fans are running. It sounds as if one or both of your fans may be faulty.
The typical fault is a 10 to 15 minute delay for the first use of the day, then it works ok for the rest of the day. Cutting in and out, or warming up when you slow sounds as if it may be some other problem.
From what you describe on your 2009, you need to verify that your fans are running. It sounds as if one or both of your fans may be faulty.
The typical fault is a 10 to 15 minute delay for the first use of the day, then it works ok for the rest of the day. Cutting in and out, or warming up when you slow sounds as if it may be some other problem.