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Can't seem to get it right Pages: 12

badufay on Tue September 18, 2007 7:58 PM User is offline

Year: 1998
Make: VW
Model: golf
Engine Size: 2.0
Refrigerant Type: 134-a
Ambient Temp: 85
Pressure Low: 25
Pressure High: 210
Country of Origin: United States

Last week my compressor took a dump on me. Since I was going to have the system opened I decided to replace the expansion valve and receiver/dryer as well. Right before the compressor died on me the system was ice cold!!!! When I was at the shop evacuating my system, we were only able to pull out 1.05lbs of r-134a. I replaced all the listed components, and had the a/c charged with about 1.7 lbs (800grams +/- 50 is spec). The a/c is working, but it just doesn't seem as cold as it used to be. A stuck a thermometer in the vent and it only gets down to about 50 degrees F (outside temp is between 80-90). Is this normal? Is it possible the system operated better with that low charge? And now I am afraid to ask this question, but what about all those "a/c boosters" and synthetic blends that make the air colder, is there any truth to that? Any help or ideas would be appreciated.

Thanks,
Ben

Wet in Washington on Tue September 18, 2007 8:08 PM User is offline

"a/c boosters" and synthetic blends that make the air colder, is there any truth to that? In one word, NO. That stuff is nothing but "Snake oil". I guarantee you if you use that stuff it will screw up your system for sure. I would stay away from anything that claims it will give you colder air.

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Never take life seriously. Nobody gets out alive anyway.

Chick on Tue September 18, 2007 8:10 PM User is offlineView users profile

Is the fan operating properly? Did you insulate the expansion valve the same way it was? I believe the valve has a black plastic 'box" that snaps over it, I do see a lot of them where they leave it off..Did you flush the system? did you get all the flush out? How did the other compressor fail, and what brand was you new/reman?? How much, and what type of oil did you add back?

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

badufay on Tue September 18, 2007 8:52 PM User is offline

The fan is working properly, and yes the expansion valve insulation is in place. The flush was completely removed, and the system has no leaks. I added about 2.5 oz of pag oil to the compressor (that number came from VW). The compressor just slowly started to fail (couldn't create any pressure). I am not sure of the brand. What should my temperture be coming out of those vents?

Chick on Tue September 18, 2007 9:05 PM User is offlineView users profile

If the system was flushed, you need between 4 and 4 1/2 ounces of PAG 46 viscosity oil in the system. (system total) Your other compressor failed most likely due to a variable dosplacement valve failure. Common on those.. Vent temps will vary with heat and humidity, try lower fan settings and see how much they drop, also try spraying a "mist" of water on the condenser..If the high side drops like a rock, you have air flow proplems..If it drops slowley, you can rule that out.. I say this because the VW's I have worked on usually have a high side around 2.2 times ambient, (185-190psi at 85 degrees ambient) yours seems a bit high, not much, but enough to check the airflow to rule it out.. Low side shows good cooling, be sure that the suction line going back to the compressor is cold..Let us know what you find..Hope this helps..

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

badufay on Tue September 18, 2007 9:24 PM User is offline

I will get that oil added ASAP. I checked the air flow thing and the pressure on the high was pretty slow if at all the react. I placed another fan in front of the car and it too slowly dropped the high side, so i don't think it is an airflow problem. the low line is nice and cold as well. any other ideas?

Ben

Chick on Tue September 18, 2007 9:27 PM User is offlineView users profile

Seems to be working, try the lower blower speeds with windows up..After you add the oil before you ruin this compressor... You could also check the blend doors to be sure they are closing..Your low side pressures indicate good cooling, and the cold suction line confirms it...

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

badufay on Tue September 18, 2007 9:47 PM User is offline

ok, I will try this all out. ill post my results tomorrow.

Ben

badufay on Wed September 19, 2007 5:02 PM User is offline

yeah, i just got back from a highway drive and the a/c held steady at 48-50F. I am wondering if maybe the expansion valve i put in was more of a one size fits all instead of a vw original (i am trying to think of anything). This is the valve i bought, http://www.autohausaz.com/search/product.aspx?sid=bxdpeu55d2nkc1ncqhlkcr45&[email protected]&[email protected]%20&year=1998&[email protected]%20%26%20Heat%20-%20Climate%20Control&[email protected]%20Expansion%20Valve . Any ideas?

Ben

TRB on Wed September 19, 2007 10:20 PM User is offlineView users profile

Was each component flushed individually to remove oil and debris? Was any component that was not replaced not flushed?

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badufay on Wed September 19, 2007 10:57 PM User is offline

the only things that were not replaced were the evaporator and the condenser. Those were both flushed and cleaned. everything else is new. any thoughts on the expansion valve? Another thing. My wife's jetta (exact same set-up), which i also replaced the compressor, expansion valve and drier, pretty much blows at the same temp. I bought the same parts from the same place. (serviced at 2 different locations) thats why I am thinking maybe the expansion valve. Or, possibly the system ran a lot better at 1.1 pounds? I don't know, at this point i am open for any suggestions.
Thanks,
Ben

TRB on Thu September 20, 2007 12:00 AM User is offlineView users profile

To be honest with you I can't speak for what another company sells. Vendors I know don't have generic valves and OE valves. Some valves have different settings and tonnage for different vehicles. But again no way for me to know by looking at that link. I would ask the vendor or break out the wallet and get an OE valve if you think it may be the issue.

How much oil is in the system?

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badufay on Thu September 20, 2007 8:46 AM User is offline

i added 2 oz before the drive yesterday, so the total system is at about 4.5 oz.

Ben

TRB on Thu September 20, 2007 10:51 AM User is offlineView users profile

Vehicle listings.

Sanden SD7
Oil capacity 4.0 ounces but I would use 5 ounces myself.

Refrigerant capacity: 28 to 29 ounces

Low Side Pressure: 18 PSI
High Side Pressure: 203 PSI

Pressures listed at 80 degrees ambient and 1500 RPM. Listed pressure are a guide!


That said are these compressor China knock offs or real Sandens?

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

badufay on Thu September 20, 2007 6:47 PM User is offline

The compressor is a rebuilt unit by ready-aire. I have some more temp readings:
Outside temp was 91', and the car was driving on the highway at about 60mph, engine rpm about 2500ish. recirc air on, fan speed 4 (max) temp, 56. on 3 it went down to 52, at 2 it was about 49, and on 1 (low) it was 48. Even after it cooled down outside, to about 70F, the temps stayed the same. both lines on the dryer are about the same temp (hot). A little more background, my wife has a 98 jetta and i recently replaced the same components (same brands and everything) on hers, and the temp results are the same. the pressures indicates to me that the compressor is working correctly. for some reason the only thing i can think of is the expansion valve. it is not an oem part, it is made by CRP-Continental/TGK. Is this a possibility that this valve is "acceptable," but not truly oem quality. I know the basic principle of its purpose, but how and what specs they are manufactured to, i don't know. I am getting ready to order the valve from the dealership, to possibly rule this out. Any other ideas?
Thanks,
Ben

Edited: Thu September 20, 2007 at 10:46 PM by badufay

ice-n-tropics on Fri September 21, 2007 9:36 AM User is offline

Ben,
The Sanden SD7V10 variable displacement compressor is available with 5 different control valve suction pressure settings. Remanners don't know or don't care and figure one setting valve is OK for all applications. Hence, the compressor destroks prematurely on about half their compressor applications. Also, if the refrigerant charge amount is low.
You could buy a new model #1100 from AMA (with your refund on the reman) if optimum performance is a big deal with you. I'm pretty sure Tim would have steered you toward new, if you would have asked.
The OEM TXV valve is supplied by TGK, so don't change it.
Cordially,
Old IV guy

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Isentropic Efficiency=Ratio of Theoretical Compression Energy/Actual Energy.
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HECAT on Fri September 21, 2007 10:15 AM User is offline

Quote
Originally posted by: badufay
The compressor is a rebuilt unit by ready-aire.

I am going to second the "should have got new one from Tim".

The success of a repair on one car with certain products cannot be compared to another. The variables involved become boggling as you sit and ponder. The brand you mentioned has a "hit and miss" kind of history and fits with your "it fixed the other one, but not this one" scenario.



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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

Chick on Fri September 21, 2007 2:51 PM User is offlineView users profile

"The compressor is a rebuilt unit by ready-aire. "
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opps, sorry....Wouldn't use those...

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

TRB on Fri September 21, 2007 2:54 PM User is offlineView users profile

Thanks guys, and yes I prefer new compressor over remanufactured.

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

badufay on Fri September 21, 2007 4:21 PM User is offline

I pretty much figured that about the compressor. I tried saving a few bucks, but i guess some of us have to learn the hard way. For now, it seems to be working to an "acceptable standard," it should suffice until I leave for Iraq in a few months. Maybe when i get back, i will replace it with a brand new one. Thanks for everyone's help with this, and I will definitely bookmark this site to track down a new compressor when i return in 2009!
Thanks,
Ben

Chick on Fri September 21, 2007 4:32 PM User is offlineView users profile

Be safe, the AC will wait..Thanks for your service to our country...

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

TRB on Fri September 21, 2007 4:42 PM User is offlineView users profile

Yes please be as safe as you can be. As chick mentioned thank you for serving our country!!

If you get a chance keep us posted on your time in Iraq. I personally would love to here the facts from boots on the ground!

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

HECAT on Fri September 21, 2007 5:21 PM User is offline

Good luck Ben, and thank you so very much.

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

badufay on Sun September 23, 2007 12:00 AM User is offline

I did notice something about the a/c today. The bottom line on the condenser seems to be about the same temp as the top. I can't see anything restricting airflow to the system, but i would assume there would be some sort of significant temp drop. I am now wondering why the high speed fan won't click on, just the first stage. However, i don't think i am to concerned with the fan since highway speed doesn't change the temp. What could be (about) the temperature change from the inlet to the outlet on the condenser (again, its on a 98, vw golf)?

TRB on Sun September 23, 2007 2:10 AM User is offlineView users profile

About 40 degrees is normal.

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

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

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