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98 passat Cooling issue Pages: 12

Jhorkey on Thu April 02, 2009 1:06 PM User is offline

Year: 1998
Make: VW
Model: Passat
Engine Size: 1.8t
Pressure Low: 100psi
Country of Origin: United States

So ive got a 98 1.8t with manual controls and i had problems with the AC the first day i got it, but they guy i bought it from got it fixed for me. now almost a year later and ive got no cold air. when i press the "AC" button the air seems to be the slightest bit colder but nothing like it used to run. i was using the ac during the winter so it was being used. I figured i just needed a recharge, so i picked up a kit and the pressure was over 100psi. my dad told me that he doesnt hear any difference between when i have the AC engaged or not engaged. the only difference is that the secondary fan turns on. i read about the relay, i think 384 or something, but i cant seem to locate it.
any help would be greatly appreciated.

robs on Thu April 02, 2009 1:37 PM User is offlineView users profile

we have had issues that VW Passats/Jettas in our shop with the expansion valve going bad on those vehicles. A quick way to determine if the expansion valve has quit working, is to put the gauges on and if the low side goes into a vacuum then that's your problem.

Edited: Thu April 02, 2009 at 1:46 PM by robs

Jhorkey on Thu April 02, 2009 1:41 PM User is offline

I put the gauge on the low side and it was at aprox. 100psi
this of course was with the car off

Edited: Thu April 02, 2009 at 2:02 PM by Jhorkey

Jhorkey on Thu April 02, 2009 2:09 PM User is offline

and the reading did not vary, it was a solid 100psi

robs on Thu April 02, 2009 2:38 PM User is offlineView users profile

so what are your high side readings? actually can you give me both readings with the car running and a/c on.

Edited: Thu April 02, 2009 at 3:31 PM by robs

Chick on Thu April 02, 2009 6:07 PM User is offlineView users profile

The variable displacement compressors on those have a problem with the refrigerant control valves. But you will need to recover the refrigerant and recharge to make sure the "full" system charge is in the system. If the pressures remain the same, then it's time to change the compressor, the control valves in those are really not DIY friendly. Check the sponsors quality remans and new.. Hope this helps..

-------------------------
Chick
Email: Chick

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Freedoms just another word for nothing left to lose

Jhorkey on Thu April 02, 2009 6:20 PM User is offline

Quote
Originally posted by: Chick
The variable displacement compressors on those have a problem with the refrigerant control valves. But you will need to recover the refrigerant and recharge to make sure the "full" system charge is in the system. If the pressures remain the same, then it's time to change the compressor, the control valves in those are really not DIY friendly. Check the sponsors quality remans and new.. Hope this helps..

Im confused what i need to do? do i just need to do a system recharge?

Chick on Thu April 02, 2009 6:37 PM User is offlineView users profile

A system recharge will tell you if the refrigerant control valve inside the compressor is working properly. If it is, it will begin pumping as it's recharged, if not, you will need to change the compressor..Hope this helps.

Variable displacement compressor tend to equalize the pressures when not fully charged. GM has an easily changed control valve, but VW is not an easy one, it takes dismantling of the compressor to change the valve..

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

Edited: Thu April 02, 2009 at 6:39 PM by Chick

robs on Thu April 02, 2009 6:40 PM User is offlineView users profile

Click HERE to read a similar topic in the forum that answers a lot of questions you might have and informs you of what tools you might need to read the system properly and/or parts to service it.

Edited: Thu April 02, 2009 at 6:41 PM by robs

TRB on Thu April 02, 2009 6:42 PM User is offlineView users profile

Do you have access to a set of a/c gauges, vacuum pump and tools need to repair your vehicle? As the other posters have stated this system will only work with the proper amount of refrigerant in the system. You might have a leak in the system. Doing a dye or electronic leak check should be done at this point. If no leaks are found reclaim the refrigerant pull a vacuum and recharge with R134a to the OEM specifications. If you still have cooling issue at that point posts the pressure readings at idle and 1500RPM.

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Jhorkey on Thu April 02, 2009 8:58 PM User is offline

I have the AC gauges but the connection doesnt work for my cars connection. so i guess i do not

Chick on Thu April 02, 2009 9:06 PM User is offlineView users profile

You do need a good gauge set, check these mastercool sets out. Great for the DIY'er. Or you will need a shop to do the diagnosis for you. But my guess is the compressor.. Hope this helps..

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

Jhorkey on Fri April 03, 2009 12:32 AM User is offline

i already have the gauges, but not the hoses? can i get that at my local auto parts store?

TRB on Fri April 03, 2009 12:35 AM User is offlineView users profile

If you have a set of R12 gauges. You can use these couplers on your current hoses to adapt to the R134a service ports.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

Jhorkey on Fri April 03, 2009 12:51 AM User is offline

is it really worth getting the couplers? or should i just take it somewhere and get it flushed and recharged and then check for leaks?

TRB on Fri April 03, 2009 1:16 AM User is offlineView users profile

Quote
Originally posted by: Jhorkey
is it really worth getting the couplers? or should i just take it somewhere and get it flushed and recharged and then check for leaks?

I just provided you an option for converting you R12 gauges to R134a so you could check the pressures as mentioned. I don't see why you would need to have the system flushed, as you don't even know what is wrong at this point. Flushing is required after a compressor failure, have you had a compressor failure? While working on an auto a/c is not hard! It yet requires some tools to diagnose the problem. So it really is up to you if you want to try and work on an a/c system or not. If you're not familiar with an auto a/c system Mastercool has a good DIY repair manual which could help you understand the basics.

-------------------------
When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com


Edited: Fri April 03, 2009 at 1:18 AM by TRB

Jhorkey on Fri April 03, 2009 1:58 AM User is offline

what will the pressure show? what can we learn from the pressure? do i need both the high and low sides?

TRB on Fri April 03, 2009 5:17 PM User is offlineView users profile

Quote
Originally posted by: Jhorkey
what will the pressure show? what can we learn from the pressure? do i need both the high and low sides?

It will show if the compressor is working correctly. It can show a low refrigerant level. Yes one must to have both pressure readings at the same time I.E Real gauges for diagnostic purposes. If one understands what pressure readings mean at certain operating conditions, pressures can tell a lot more than I can type in 30 minutes.



-------------------------
When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

Jhorkey on Tue April 07, 2009 5:25 PM User is offline

i ordered the couplers, hopefully theyll be here by the end of the week

TRB on Tue April 07, 2009 5:35 PM User is offlineView users profile

Quote
Originally posted by: Jhorkey
i ordered the couplers, hopefully theyll be here by the end of the week

Sorry I can't provide a tracking number as I don't see an order with us for couplers lately.



-------------------------
When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

Jhorkey on Wed April 08, 2009 1:13 AM User is offline

ill let you know when i get them

TRB on Wed April 08, 2009 2:23 PM User is offlineView users profile

Hopefully with some research and the addition of the couplers AKA pressures readings you will find out what is wrong with your system.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

Jhorkey on Wed April 08, 2009 4:19 PM User is offline

thats what im shooting for!

Jhorkey on Thu April 09, 2009 5:21 PM User is offline

ok so i took the readings today, on both the high and low side with a legit A/C gauge while the car was running and while it was off
High side
off-65
on-56

low side
off-62
on-60

Chick on Thu April 09, 2009 5:39 PM User is offlineView users profile

Change your compressor along with the drier and expansion valve.. Your's is dead.. Hope this helps..

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

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