Delayed Air Conditioning

Luis G

Well-known member
Joined
Aug 19, 2008
Location
Kyle, Texas
TDI
2006 Jetta
Might just be the pressure sensor is not seeing the proper pressure in the system when the system has not been used in awhile. i.e. car sits over night.

while the car is warming up the pressure builds in the AC system due to the extra heat in the engine compartment and finally triggers the pressure sensor.

Sound like the compressor is working fine once it starts and stays working after the car is warmed up. So I don't think it would be the compressor.

Pressure sensor is very easy to change and only about $60.
 

DanG144

Top Post Dawg
Joined
Aug 2, 2007
Location
Chapin, South Carolina, USA
TDI
2005 A4 Jetta 5spd
I got the following information off of ZIG TDI's 2006 BRM. At least we read them as best we could...
Brand: Sanden
"Manufacturer Code" ZJX
Model: U8676A
Oil Amount: 1100cc
Oil specs: SP-10
Seriel #: 01132811570
Product #: 1K0 820 803 Q
 

glandpuck

Well-known member
Joined
May 19, 2007
Location
MI
TDI
2006.5 Jetta TDI DSG Pack2
Jerry M. it looks like your AC is working nicely. Now, I have read lots of comments about not turning on the AC until the engine is warmed up, etc. This is rubbish and misses the point of all of these AC discussions: These Jetta's all were delivered from the factory with AC that went on immediately and blew ice cold! Now, they delay in going on and maybe don't blow as cold. This has nothing to do with the outside temp or the engine not warming up. It has everything to do with part of the AC system not working to factory specs. Which part is it? Is it the pressure sensors? Is it the expansion valve? Is it the flow valve on the compressor? Is it the compressor itself? Is it the ECM? Is it the fan controller? Please remember that the compressor installed on the Jetta (primarily Sanden PXE16 @ www.Sanden.com) is a pretty advanced piece of technology and also not unique to the Jetta or even VW. Therefore, if it is a compressor problem, it should be a problem in all of the other compact cars sold on the planet using this model series of compressor as well as 2007, 2008 and 2009 Jettas.

I have decided to take the slower, possibly cheaper or more costly route to fix this problem. I am going to replace my expansion valve and drier. Iif that doesn't work, maybe the pressure sensors next and lastly the compressor. If none of that works, the fan and lastly maybe the ECU. If all else fails, I can take the car to the dealer or sell it in the winter!!!!! But I will not give in to this AC problem and be hot in my car.

DanG144: By cycling on and off i meant that the high pressure stayed at a constant, rather than fluctuating up and down as in other AC systems (like GM)
 
Last edited:

christylea

New member
Joined
Aug 4, 2009
Location
Austin, TX
TDI
Jetta
Rauss said:
This is a new generation fuel efficient ac system... that`s why. It use the heat of the motor, and exchange air from outside to create cold air... sucks but fuel efficient... want some ac power get a old GMC or something like this.
Out of curiosity - what is considered "normal operating temp" anyway?
 

rich!

Active member
Joined
Apr 27, 2009
Location
SoFLA
TDI
Touareg
chemeng1661 said:
I have the issue as well. On very hot days (like it has been in NJ for the past week), it takes awhile (about a half mile) for the air to blow ice cold.

Also, over the past week, I noticed that the air periodcally starts to blow warmer, especially when at slower speeds (bumper to bumper traffic), then it gets ice cold again. It is really annoying. I haven't observed this before on the car.

I checked the fans twice on my most recent trip home and both were running. I really do not feel like visiting the dealer's service department for this. I have 5100 miles on the car.
Starting to notice the same thing (@4500 miles). Some days the air will blow cold at start up and others it may take 10 minutes of driving around (while its still "cold" its nowhere near the bone chilling on normal days) - This in SoFLA and running the A/C everyday.
 

Luis G

Well-known member
Joined
Aug 19, 2008
Location
Kyle, Texas
TDI
2006 Jetta
glandpuck,

You should replace the pressure sensor first, You can replace without loosing any of the refrigerant, and its only like $60.
 

dbdubb

Veteran Member
Joined
May 21, 2006
Location
Tampa, Florida
TDI
06 Jetta, 10 Q7
Is there any update here? I have similiar symptoms with my 06 now at 107,000 miles. Just curious if you found a resoloution.
 

glandpuck

Well-known member
Joined
May 19, 2007
Location
MI
TDI
2006.5 Jetta TDI DSG Pack2
Delayed AC

I have posted before. I have had measured pressures, looked at my fans, put the VAG-COM on, replaced the drier and expansion valve. I was told by the mechanic replacing the parts the system was clean and I needed a new compressor. i went to order my new Sanden and was told by the merchant, after I revealed my problem and my measures compressor pressures that i did not need a new compressor.
Well, the choices were clear: Buy a new AC pressure switch, buy a new compressor, or dealer. Today, I took the car into the dealer and the diagnosis was I needed replacement of the small cooling fan (passenger side), even though the VAG shows the fan running, it does not tell which one is running. My car has all the same symptoms, but when you finally get on the freeway and travel 70, the AC blows pretty cold.

I was quoted $535 to replace this fan, about $600 if the large fan goes next, or about $960 to replace both of them.

So now I am going to look for a good aftermarket fan. If anyone had a source for a good European fan, please PM me.

2006 TDI

Thanks,

Robert
 

Turbine Suburban

Veteran Member
Joined
Jul 12, 2009
Location
Upstate NY
TDI
2009 6 manual Gone! V6 Mustang now.
I have seen a page somewhere concerning the cooling fans, it seems that with many of them, if you are willing to take them apart, they can be fixed. the brushes get cocked out of place, and can be re-positioned.
 

nic_a_bod

Veteran Member
Joined
Aug 30, 2006
Location
sw wisconsin
TDI
2005.5 Jetta
I have a similar issue - seems like my AC doesn't work for a few miles also when the car is sitting out on a nice hot day and I don't crack a window. The cabin gets extremely hot and my issue seems to pop up. I checked the fans, both spin when the AC is turned on.
 

elester12

Veteran Member
Joined
Feb 25, 2009
Location
Washington DC
TDI
2010 TDI
Hey guys,

I had this issue with my 2007 passat. The shop foreman replaced EVERYTHING on my car. He replaced the sensors and even the unit in the dash that controls the fan speed etc. In the end he replaced the compressor and the delay went away. we realized there is a certain compressor brand which causes these issues. The shop tech told me about a time where he replaced a compressor and it still had the delay. He realized it was the brand. This may not be everyone's issue but it was mine for my Passat. I took the car in 11 times to get the issue resolved :p
 

wild03

Veteran Member
Joined
Jun 26, 2009
Location
Miami FL
TDI
:(
:mad:
Hey guys,

I had this issue with my 2007 passat. The shop foreman replaced EVERYTHING on my car. He replaced the sensors and even the unit in the dash that controls the fan speed etc. In the end he replaced the compressor and the delay went away. we realized there is a certain compressor brand which causes these issues. The shop tech told me about a time where he replaced a compressor and it still had the delay. He realized it was the brand. This may not be everyone's issue but it was mine for my Passat. I took the car in 11 times to get the issue resolved :p

holy crap! I had this happen today, car had been sitting for more than 24 hours. Day was cloudy, low 90s or high 80s, not terribly hot inside car. I start the AC with recirculate on. NOTHING for half a mile...then BOOM AC is cooling nicely.

Never noticed this before. would hate it for it to be a compressor issue. What a piece of #$% this car has turned out to be. :mad:

will keep an eye on it.
 

Claudio

Veteran Member
Joined
Oct 30, 2009
Location
IL
TDI
09 Jetta SW
Weird one here folks - it seems that my AC begins to cool only after the car has run several miles. It's been like this for over a year, and it's really more of an annoyance than anything else. This condition only happens after the car has been sitting for a day or so. The AC works immediately once the car has been warmed up, or if the car has only sat for an hour or two.

Anyone else experience this? My wife's 2006 never seems to have this problem.

Time to recharge the AC? I'm loathe to do that, as it's probably special refrigerant, right ;)

Rob
i had the same issue, VW was saying that it was working fine which it wasn't since i needed 10-15 min before i can get cold air.
One time they forgot to reconnect the drain with the result of 1 inch of water inside my car. I brought the car back to the shop and i was so pissed that they replaced the air compressor, and it is working fine since then
 

Mach1

Vendor , w/Business number
Joined
Sep 27, 2005
Location
Spicewood, Tx.
TDI
05.5 Jetta 5 spd, 06 Jetta DE DSG, 04 F250 6L, 2000 F250 7.3L
There is a huge difference in the 05.5 BRM I have with the climatronic AC(which comes on instantly) and the 06.5 DE my wife drives, even she likes says Your Ac works way better then hers...

It has to be the ECM control, they have some kind of delay in the AC operation.

It might help if we know if its the difference in the year models or if its the difference between the climatronic VS. the standard AC...
 

DanG144

Top Post Dawg
Joined
Aug 2, 2007
Location
Chapin, South Carolina, USA
TDI
2005 A4 Jetta 5spd
There is a built in delay time. But it has never been the culprit on any problem cars that I have seen, it is just too short to cause a lot of notice.
On the cars I have seen data for (only 3), the current signal to the compressor control valve was at full demand - but the compressor was not responding.
I would like to see more data from more cars.
The ECM control signal is easily seen on VCDS. It was not the cause.
Once the compressor control valve is getting full demand, that is all any control system can do.
 

scurvy

Good Ol' Boy
Joined
Feb 21, 2006
Location
Chicago IL USA
TDI
2006 Golf
This is a new generation fuel efficient ac system... that`s why. It use the heat of the motor, and exchange air from outside to create cold air...
:confused:

Aside from making a heat engine, how exactly does your imaginary system work?

The AC system on Volkswagens is a straightforward system in operation, pretty much the same as it has been for the past hojillion years - a refrigerant compression/expansion system. Even old GMCs use the same technology. New ones do too.

R134a has been in use for the past 20 years in automotive AC systems (mandatory since 1996, IIRC). Nothing about this system is 'new' and the only remotely 'novel' thing about it is the variable-displacement compressor.

Always let the car (U.S./Japanese/German) get to normal operating Temperatures,,,, then turn on the Air.
Utter bollocks. When the system is working as designed the AC system will make cold air instantly after starting. There's no reason at all not to turn it on whenever you need it. After all, that's the whole point in having air conditioning.

Both my cars make cold air when engaging the AC almost immediately after starting. And with my wife 8 months pregnant in a foul Ballimer summer you better believe she's using the AC all the time. Any car that needed to be at 'normal operating Temperatures' to turn on the AC would get fixed, traded or pushed into the bay.
 

wild03

Veteran Member
Joined
Jun 26, 2009
Location
Miami FL
TDI
:(
There is a built in delay time. But it has never been the culprit on any problem cars that I have seen, it is just too short to cause a lot of notice.
On the cars I have seen data for (only 3), the current signal to the compressor control valve was at full demand - but the compressor was not responding.
I would like to see more data from more cars.
The ECM control signal is easily seen on VCDS. It was not the cause.
Once the compressor control valve is getting full demand, that is all any control system can do.
Count me in if you need more data, I have VCDS, just tell me the procedure you want me to follow.

I tried the AC today again, same issue, This morning was cloudy, confortable 80's for me. no need to use AC, but I wanted to see. So I turn it ON and nothing. looked in the engine bay, Compressor clutch was engaged and Fans were off. Top compressor hose (high pressure?) was slightly colder than ambient. Drove it for 300 yards or so, nothing. I turned AC off. then drove 5 miles or so until engine was at operating temperature. tried AC again, instant cold.
 

wild03

Veteran Member
Joined
Jun 26, 2009
Location
Miami FL
TDI
:(
DanG144 said:
001,1,Code for,Compressor off
001,2,Engine Speed,,Display Range: 0...10000
001,3,Driving Speed,,Display Range: 0...255
001,4,Standing Time,,Display Range: 0...255

002,1,Compressor,Current (actual)
002,2,Compressor,Current (specified)
002,3,Compressor,Rotations,Display Range: 0...10000
002,4,Compressor Load,,Display Range: 0...18

003,1,Coolant,Pressure,Display Range: 0...51
003,2,Radiator Fan,Activation (actual)
003,3,Radiator Fan,Activation (spec.)
003,4,Engine Speed,(increase)

I would be interested in seeing measuring block 1, fields 1 and 4, and measuring block 2 fields 1 & 2 and measuring block 3 field 1.
I would like to see this data for a cold start, parked overnight at least until it starts working well. Then a hot start, until it works well again.
Hi Dan, Finally had a chance to try this, I had the car off the entire day Friday, so this morning was a good time to try this, Unfortunately the AC started working with the minute, Notice the numbers below with the Car idling with AC off, then AC on with no noticeable cold air then with noticeable cold air.

What I did different today is that I did this test with the car parked, I started the car, then turned AC on, Initially it was not cooling and engine sounded like it was running a little rough, I revved (2500rpm) it a bit and noticed AC cooling. Maybe the days it does not cool right away all it needs is a little RPM to get things going?

Next time someone has this issue, can you please try putting car in neutral and revving to 2500rpm to see if AC kicks in.

AC OFF - AC ON - AC cooling
001,1 7.0 0.0 0.0
001,2 800 800 800
001,3 0.0 0.0 0.0
001,4 4:00 4:00 4:00

002,1
002,2 0.000 0.820 0.820
002,3 0 1000 1000
002,4 0 3.3 6.7

003,1 7.8 7.8 12.4
003,2 4.8% 4.8% 28.8%
003,3 0.0 0.0 54%
003,4 OFF ON ON
 

DanG144

Top Post Dawg
Joined
Aug 2, 2007
Location
Chapin, South Carolina, USA
TDI
2005 A4 Jetta 5spd
It is also interesting to note the difference between requested and actual fan speed. I have never noticed the difference to be that high before.

As you can see once you get to where you have full .820 amp control current requested, the compressor should start pumping right away, and it did not. This would seem to further indicate that the compressor's electrically driven Refrigerant Control Valve (RCV) is sticking - which is what I have thought on all the other delayed AC cars (A5's - not Passat's which have relay issues.) I also do not think the compressor is always loading fully even when it starts to work.
 

07six-o

Veteran Member
Joined
Jan 28, 2008
Location
tx
TDI
TDI
Mine still does this! Hope someone can find the cause of this because the dealer has done everything and now they said it just takes time because its so hot outside. It didnt do this when I bought the car why would it start now... the dealer is a joke!

Lonnie
 

07six-o

Veteran Member
Joined
Jan 28, 2008
Location
tx
TDI
TDI
Lonnie,
Were you the person that had also changed out the compressor, and it still did not solve the problem?
Dan
Yes! I have had two because they said something about a part that was connected to the compressor that goes out. But it is still doing the same thing. They said that they asked VW about it and there response was the ac can take up to 10min to get cold on hot days. That was the last straw for me with the dealer and VW! I am taking to a place Thursday that works on nothing but VW's so I hope they can figure it out.

Lonnie
 

robs411

Member
Joined
May 31, 2010
Location
Florida
TDI
noneyet
Not sure if this is related however my air is cool, on "4" (full fan speed) with the AC running, and "3" is acceptable but not great. I just purchased my car so I thought that is just how it was however I am questioning that now. I will put a thermometer in it and see what temps I am getting, what should I be looking for?

-rob (hot sunny FL)
 

07six-o

Veteran Member
Joined
Jan 28, 2008
Location
tx
TDI
TDI
Did the compressor change out help at all? Did it work for a while?

Please determine what brand of compressor and model you have in your car.

Dan
No. It still had the delay!

I tried to look for a number on the compressor but cant get to it to read. I would think the dealer would use VW parts right. Each of the compressors were done at the dealer if that helps. I might be able to get a mirror and read the sticker on the front side of the compressor when I get home tonight.

Lonnie
 
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