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Not cooling please help ! Pages: 12

jameshobbs on Sun July 03, 2011 10:28 PM User is offline

Year: 2002
Make: Saturn
Model: Vue
Engine Size: 2.2
Refrigerant Type: 134A
Ambient Temp: 90
Pressure Low: 25 - 28
Pressure High: 125-140
Country of Origin: United States

Friend was told by A/C shop compressor front seal was leaking reason for freon loss. Put a new ( not rebuilt ) compressor and receiver-drier added 6oz of PAG oil 150 ( came with new compressor ) added 1 oz of PAG 150 with dye. (Note list on this site says to use PAG 100 ? ) Pulled vacuum for 30 min. turned pump off it held it for 10 min. Pumped down for another hour or more
Per list on site 24 oz needed for car added 2 12oz cans my cap that hooks to cans was leaking some of it leaked out so not sure if it got all of it in. Holding idle up to 1500- 2000 RPM low side 20 -25 high 100-115 90 degree day. blowing 90 degree air out of ducts in car.low side tube from expansion valve was not cold.
Thought maybe it needed a little more R134 I have a 30 lb bottle added until low side 28 -29 high 140-150 ish low side tube from expansion valve was still not cold. still blowing 80 degree air inside. Fans are working up front so air is moving across condenser.
Drove down road at 50 miles a hour cooling some out of ducts maybe high 50s.
I know close only counts in Thermonuclear Warfare and hand grenades but I feel I should be close on freon and should be getting SOME kind of cooling at 2000 rpm with a gauge readings of 26 - 28 low side 140 - 150 high side and the fans A/C and engine fan pulling air across the condenser
Why is it cooling down to high 50s running down the road ? low on freon? / high on freon ? grill, radiator and condenser are all clean no blockage I can see. Please let me know with you guys think you all have helped before. I thank you in advance for you input !
Thank you very much ,Randy Hobbs

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Life is not measured by the number of breaths we take - but by the moments that take our breath away
Thanks, Randy

bromodragonfly on Mon July 04, 2011 12:05 AM User is offlineView users profile

With 30psi suction pressure, temp at the evaporator inlet should be close to 30F. Meaning the outlet of the TXV (not the small capillary tube and bulb, just in case there's any confusion), should be around 30F.

If you're at idle, suction pressure is 30psi, and you confirm that the outlet of the TXV is not cold at all, this is a sign that there is no liquid refrigerant flashing across it. Either it is not creating a sufficient pressure drop, or there is a lack of liquid at the TXV inlet.

Pressures seem low though, especially high side, and especially because your ambient is quite warm. But I am not going to assume an undercharge, because you added two 12oz cans (almost), and then added additional refrigerant on top of that. I think an overcharge would lead to much higher head pressure, and would produce more cooling than what you're experiencing. Both pressures are low, which doesn't point to an obvious restriction in any of the two sides. Low high side pressure is not a sign that your condenser is restricted or doesn't have enough airflow.

Stuck open TXV would flood the evap with liquid, and suction pressures would be much higher. Stuck closed TXV would raise head pressure and starve the low side, stuck partially closed would still result in flashing, and the outlet of the TXV would be quite cold.

Sorry if I'm stating the obvious here, I like to type out my train of thought as it happens, it helps me narrow things down.

My guess is your new compressor is bunk. High side pressure is too low - with 150psi discharge, condensing temperature is around 113F, which is about 20 higher than ambient. You will not be getting much liquid, and minimal subcooling at that pressure. Perhaps when you're driving down the road, with higher RPM and higher high-side pressure, and greater, cooler airflow, you're able to get some liquid forming in your condenser, which is why you're experiencing some cooling, but not much.

EDIT: sorry, I neglected to factor in the possibility that your compressor may have some kind of capacity control, such as a control valve or etc, that could affect pressures. There are many people here that are much more knowledgeable than me, when it comes to automotive compressors, and I'm sure they'll chip in.

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There is no knowledge that is not power

Edited: Mon July 04, 2011 at 9:11 PM by bromodragonfly

jameshobbs on Mon July 04, 2011 8:39 AM User is offline

Thanks , bromodragonfly
Anyone have any other Ideas ?

-------------------------
Life is not measured by the number of breaths we take - but by the moments that take our breath away
Thanks, Randy

JJM on Mon July 04, 2011 11:25 AM User is offline

If only the front seal was bad, why replace the whole compressor? Seal is around $20 or so, and even with the tools, it's still cheaper than a new V5.

Where did you source the new compressor from?

It sounds as if the control valve or mechanism is stuck and the compressor is destroking. But before we condemn the new compressor and/or its control valve, check the TXV - think it's located top right of the power brake booster - run the engine at 2,000 RPM with the A/C on while blasting the sensing head of the TXV with both cold and hot and see if the pressure readings change. If so, chances are the TXV is good, and it's the compressor (control valve or mechanism).

Also, after nearly 10 years, might not be a bad idea to replace the receiver dryer - cheap insurance.

Joe

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



mk378 on Mon July 04, 2011 3:13 PM User is offline

Variable compressor, the low side will stay around 25 over a wide range of conditions both normal and not. Except maybe for a severe overcharge which is where you are now.

It appears that the TXV is stuck closed or there's another obstruction. Are any parts getting cold?

bromodragonfly on Mon July 04, 2011 9:10 PM User is offlineView users profile

How exactly does the variable displacement compressor work? I read that the swash plate would reduce displacement when suction pressure was low (indicating a low evaporator load) therefore reducing refrigerant pumped with each stroke, and the end result would be a lower head pressure, and a suction pressure that wouldn't drop even lower. And if I think about it that way, it makes sense that the compressor could be working perfectly fine, but could be perceiving a restriction in the system as a low evaporator load.

Can a variable displacement compressor reduce its capacity to zero, or no compression? This would be the only way suction pressure would maintain itself above vacuum, and high side pressure wouldn't rise gradually, if the TXV was stuck completely closed, or if there was another large restriction in the system.

How does a severe overcharge result in low pressures on both the high and low sides, as well as zero cooling, when it comes to a variable displacement compressor?

The TXV will only modulate to be 'more open' when bulb pressure rises against spring and evap pressure, and since bulb pressure is solely reliant on superheat, and spring/evap pressure are the same, the initial TXV position when idling or driving should be exactly the same.

Technically, that TXV should be wide open if the evap is warm and the suction pressure is that low. If you're going to test it, it is best to heat the copper bulb and not the element head. Use a rag that's been soaked in hot water or something similar. If you take a flame or something extreme to a liquid-charge bulb, you could risk damaging the diaphragm by quickly creating a high pressure.

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There is no knowledge that is not power

jameshobbs on Mon July 04, 2011 9:42 PM User is offline

Thanks I will check the TXV like you said to do I was thinking it was OK because as I was filling the system the low side pulled down to 10 -15 I will let you know. His dad has a same model VUE as his but it is a V-6. I put my gauge set on it ( its working great ) it was about the same 90 degree kind of day and his low side was 22-25 and the high side was 225-240 got me thinking the compressor was not pushing enough PSI to get the job done.
But I will let you know if the TXV is working tomorrow
Thanks so much you your help !

-------------------------
Life is not measured by the number of breaths we take - but by the moments that take our breath away
Thanks, Randy

jameshobbs on Mon July 04, 2011 10:00 PM User is offline

Joe I forgot to say the guy was dead set on a new compressor .I checked with Tim at AMA ( He is the best I have used him for years ! ) for it he did not have one so the guy went to Discount AC Parts It was a new one and came with a one year next day air replacement if it is indeed bad it came with a Dryer I put it on. It also came with a TXV I did not put it on because it was cooling great just leaking freon?

-------------------------
Life is not measured by the number of breaths we take - but by the moments that take our breath away
Thanks, Randy

bohica2xo on Mon July 04, 2011 10:13 PM User is offline

The Vue is not a variable compressor - it is a scroll. The h type TXV is mounted in the engine compartment, and easy enough to get at for inspection.

Weigh in a proper charge, and evaluate the system. You could have a bad scroll compressor, because at 90f ambient & 2000 engine rpm I would expect 200psi at least, and a nasty spike every revolution of the compressor on the gauge.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

jameshobbs on Tue July 05, 2011 7:41 AM User is offline

Thanks bohica2xo , that is what I was looking for. Here in Tennessee if it's 90f day it's also 75 to 85 % humidity, So I am use to 225 to 275 high side readings and a shop floor full of condensation water. I am going to shoot a little freon on the side of the TXV and watch my gauges for a jump.
Thanks so much for your help !

-------------------------
Life is not measured by the number of breaths we take - but by the moments that take our breath away
Thanks, Randy

jameshobbs on Tue July 05, 2011 9:31 AM User is offline

I hooked the gauges up and had him hold the idle up to 2000. The low side was at 25 ish shot a little freon to the side of the TXV and it went into suction the low side gauge dropped down to 10- 15. after a min or lees went back to 25 were it was.
So Joe dose that prove the compressor is bad ?

-------------------------
Life is not measured by the number of breaths we take - but by the moments that take our breath away
Thanks, Randy

JJM on Tue July 05, 2011 9:03 PM User is offline

My apologies on screwing up this thread with the V5 error, sending our fellow members off on a wild goose chase. Nice catch, Bohica. Was I at least right on the location of the TXV?

The shot of refrigerant on the sensing head... aside from killing penguins and causing the Earth's temperature to rise a half a degree (maybe that's why a 1/3 of the US is suffering a heat wave now)... does seem to indicate the TXV is functioning. You should also do the hot test too to absolutely confirm, which should cause the suction pressure to rise. Use the hot rag method as Dragon suggested. (Note: The block type TXV in this vehicle does not have a capilary tube and sensing bulb).

In any event, it does seem like the compressor is just not pumping enough... and if it's not from Tim, the dealer, or AC Delco parts jobber, the source is questionable in my opinion.

Again, my apologies for the compressor confusion. Probably time to hang up my gauges...

Joe

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


bohica2xo on Wed July 06, 2011 10:48 AM User is offline

No worries JJ - I have the advantage of an 07 Vue parked in the driveway...

With the cold shot, it looks like either the compressor is weak, or you are somehow undercharged.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

jameshobbs on Wed July 06, 2011 10:16 PM User is offline

Put new compressor on pumped down for 30 min. added the 24 oz of 134A per chart. Low side tube felt cool it is a 80 degree evening with 70% humidity @ 2000 RPM high side 175 low 32 duct temp 60. Drove down road never dropped below 58 deg. came back put gauges on 160 high side low jumping between 35 - 40 would pull down to 35 then float back to 40 still 60 deg duct temp. This thing is KILLING ME !
To me it acts like its got to much 134A in it. I put in 2 12oz cans = 24oz per the chart on this site . Like I said his dad has a VUE just a V-6 were this is a 4 banger. on a 90 deg 80% Hum day His readings were 250 high and a steady 25 low I did not check the duct temp but I would bet 35 to 40 deg.
Should I let a little out ? My 1996 Honda with the same thermometer read 33 deg today and my 1996 dodge caravan was 40 degree today!
Now I remember why I got out of mechanic's 20 years. ago. it was Shit like this , Sorry guys I am tired and pissed off !
I believe this compressor is doing its job What should I do next ?
Thank you all so very much for all your help !!!!

-------------------------
Life is not measured by the number of breaths we take - but by the moments that take our breath away
Thanks, Randy

bohica2xo on Thu July 07, 2011 9:15 AM User is offline

You are undercharged.

Your sample vehicle is showing a higher discharge pressure, and better performance.

Add some refrigerant. Slowly. Watch the pressures. Add an ounce, then let the system stabilize for a couple of minutes at 2000 rpm.

Small differences in production vehicles, like a mid-year hose re-route or part change can alter the charge volume.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

Edited: Thu July 07, 2011 at 9:16 AM by bohica2xo

jameshobbs on Thu July 07, 2011 11:08 AM User is offline


Will do, Thanks !

-------------------------
Life is not measured by the number of breaths we take - but by the moments that take our breath away
Thanks, Randy

JJM on Thu July 07, 2011 6:45 PM User is offline

Considering where the parts were sourced from, and the fact that the compressor "came with" a dryer and TXV, to me the parts are suspect - especially the TXV. Seems like it's some kind of "universal" TXV. Granted, the TXV does appears to work, the question is if it's correct for the application. Seems like the superheat is way off.

New doesn't always equal good. I would feel a lot more confident if this part were sourced from Tim, or OEM from a GM dealer or AC Delco parts jobber.

Also not knowing the history on this vehicle... were any sealers added, has the system been flushed to ensure the absence of excess oil. If you have an IR thermometer, I wondering what kind of sub-cooling you're getting from the condenser.

Joe

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


jameshobbs on Thu July 07, 2011 11:50 PM User is offline

Does seem like it has a lot oil in it, when I take the gauge hoses off I see oil spray out some. I had let a little 134A out the other night to get the low side down to 30 or lower. A lot of oil came out while I was doing that. Got the low side down to 30 to 32 high side came down to 160 - 165 same 60 deg vent temp.
(1) You make me wonder if there is not a butt load of oil in there if so whats the best way to get some out? can it screw the TXV up?
(2) I was going to try adding like you said I guess I was confused I thought if I was trying to get the low side presser down I need to take out 134a not add? But thinking now my high side was dropping too so I do not have the presser for the TXV to do it's job right?
My thinking was when the low side was 35 floating to back to 40 then back again it had to much in it. But what you are saying it did not have enough for the presser drop / high side to do it's job ?
By the way I have not put the TXV valve that came with the kit on yet the factory one seems to be working fine My thinking was the compressor was leaking and did not have a black death or lock up so no metal / crap was pushed into the system so I was safe not changing it because it was working before with the old compressor it was just leaking 134a out of the old compressor but it was cooling good when 134a was added
Sorry for all the questions , trying to learn and fix the problem too.
Again thank you so much for all your help

-------------------------
Life is not measured by the number of breaths we take - but by the moments that take our breath away
Thanks, Randy

bohica2xo on Fri July 08, 2011 1:05 AM User is offline

It is acting like it is undercharged

If it has too much oil, pressures will be slightly above normal on the low side, and too high on the high side - with poor cooling.

If it is undercharged, Pressures will be above normal on the low side, and low on the high side.

According to the high humidity chart for the Vue, with 90f ambient & 50% RH you should see 220 to 260 psi on the high side, 21 to 28 psi on the low side, and 40 to 53f at the vents - tested @ 2000 engine rpm. That test specifies fan on third speed, with windows down - and the Tech 2 scanner overriding the condensor fans to maximum speed. Without the Tech 2, I would expect even higher pressures on the high side...

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

jameshobbs on Fri July 08, 2011 11:55 AM User is offline


Thanks so much for the great info !! I will let you know.
Thanks again !

-------------------------
Life is not measured by the number of breaths we take - but by the moments that take our breath away
Thanks, Randy

jameshobbs on Sun July 10, 2011 6:30 PM User is offline

I have two pedestal fans blowing at the front of the car. Started low 30-34 high 170- 175
It is 97 deg day with 40 % humidity ( so I am thinking I will see 250 - 290 high side reading)
I put a little in low 40 high 200 inlet feeling colder. still 60 vent temp
Added a little more low 46 low high 250- 260 .still 60 vent temp inlet cold ish
( I am letting it stabilize in between adding )
Add a little more low 48 high 290- 300 60 vent temp
Thinking I have a little much in it let it down low 44 high 250- 260
Thinking TXV not opening up shot a little 134 on the TXV low side dropped to 25 -30 ish then floated back to 45 - 48
Drove it down the road 58 lowest vent time I understand with the low side at 45.
Any ideas ?

Thanks 1

-------------------------
Life is not measured by the number of breaths we take - but by the moments that take our breath away
Thanks, Randy

Boomer_106 on Thu July 14, 2011 10:44 PM User is offline

I'll be really interested to see what the solution eventually is. You've been through quite a bit here. Hope you get it.

jameshobbs on Fri July 22, 2011 11:47 PM User is offline

Thanks it has been a bear. It takes jobs like this to remind me why I got out of auto repair 20 years ago. I will find the problem one way or the other.

-------------------------
Life is not measured by the number of breaths we take - but by the moments that take our breath away
Thanks, Randy

jameshobbs on Sun July 24, 2011 11:35 PM User is offline

Put a New TXV on it today. It is a 80 deg with 70 % humidity Pumped it down for 1 hour put 2 lb in it ( 2000 rpm) two fans blowing at the front of the car 45 -50 side 210 high ( same old crap) 60 degree vent temp. Taped gauges to windshield drove down road Low 40 high 175. Came back let a little 134a out low 40 @ 2000 rpm high 190. vent temp still 60 deg. ( in shop) Drove down road at 60 mph low 30 but a few times low went to 18-20 and then float back to 35 and come back to 27 -30. High side140-150 (high seems low to me?) duct temp 40-44 I was thinking with the low side down to 27 I would have a vent temp of 30-35 deg? At 2000 rpm sitting in the shop ( two fans blowing on the front ) 40 low 190 high duct temp 50 deg.
There is a little sensor that screws to the top of the TXV and it has a probe that goes down into the TXV it has two wires that run back to some were?
1) What does this sensor do / what is it called ?
2) How can I test it ? it is the last piece that has not been replaced ?
3) Is this sensor bad and maybe giving the computer bad info and screwing with my inside duct temps ?
This has been a job from hell but I want to fix it I have too much time invested in it to give up now!
Thanks for any help !!

-------------------------
Life is not measured by the number of breaths we take - but by the moments that take our breath away
Thanks, Randy

TRB on Mon July 25, 2011 12:33 AM User is offlineView users profile

Have you thought about buying the Mitchell or alldata subscription for this car. $20.00 and would supply you a good amount of information.

http://www.autoacforum.com/messageview.cfm?catid=20&threadid=9199

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