Engine Size: 3.8
Refrigerant Type: 134a
Ambient Temp: 92
Pressure Low: 38
Pressure High: 275
Country of Origin: United States
Need some opinions on my AC. You guys helped me out rebuilding a V5 last year and have an issue with this car. (V5 in the other car still cooling great!)
Some history: Bought the car in 09, 25K miles, 62k now. AC not working. Took it to the shop and they replaced the compressor. In 2011 the evaporator went out
and had the shop replace it. So I have $1200 in this AC and really don't want to put anymore into it. Already have more in the AC than I paid for the car.
After I got the evaporator replaced it never really seemed to cool like it did after the compressor was replaced.
I added 1 can a week ago before checking anything just to see if it helped, not too much. There is dye in the system but didn't not see any leaks
anywhere. Before I put the manifold on it I noticed some dye at the low side port, had a very short hiss when I pulled the cap off as if there was some pressure there.
Wasn't sure if the dye was from when I added the can so I cleaned the port, replaced the cap, I suspect a leak. An hour later I pulled the cap off and more
dye was there. If there's a leak then there must be air in the system , correct? I wanted to check other issues before fixing the port.
Also the dye at the port was slightly dirty. dye was still very brightly colored.
Depending on the driving condition, the vent temperatures fluctuate from the lower 60's to a bit above 70. At highway speed it the coolest, at idle it's the warmest.
Here are the gauges at Idle, 92 degrees ambient, 47% humidity, 65 degrees at the vent:
Here are the gauges at 2000 rpm, 92 degrees ambient, 47% humidity, 61 degrees at the vent:
Have searched around but haven't seen any definite answer other than air in the system but I'm not good at reading the gauges.
Any suggestions on what to check?
you do not know the exact amont of refrigerant in the system right now. You really need to recover the charge and recharge by weight the proper amount. That will eliminate freon level as a problem.
I am not able to understand your problem properly . I think you should consult professional technicians for this. One of my friend suggested me to try ALLWEEKAIRCONDITIONING for my residential ac , they have experienced technicians I am sure they will help you out with this . For more information you can just check this out .
Today around lunchtime I turned the air conditioning on and it blew only hot air. Checked it when I got home and looks
like the small leak I had at the low service port got bigger and the valve completely went out. I've already purchase new high and low side ports
and will try to do a vacuum this weekend to see if there are any other leaks. Didn't see dye anywhere else so I'm thinking this is it.
Will keep you posted.
Edited: Fri August 01, 2014 at 6:22 PM by Chriskc
I also plan on changing the accumulator and orifice tube while the system is down. I'll measure the oil that comes out of the accumulator and put the same amount in the new one.
I can only see the part number on the compressor, 6511355 and a search shows it is a Global Parts compressor. I see where GM V5's take Pag 150
but I saw a search on the Global Parts compressor it takes Pag 46. Could anyone clarify which oil to use?
Edited: Sun August 03, 2014 at 1:06 PM by Chriskc
Took the O tube out and accumulator off. Drained about 3 ounces out of the accumulator. Is this the normal amount that should come out?
If not, how much should I add back. I'm going to put Pag 46 back in there from the searches I've seen the Global Parts uses the Pag 46.
Here is what the oil looked like:
The o tube didn't look clogged up and could see light through it. Had a few minor slivers of metal
on one of the screens. Probably normal wear for a new compressor installed in 2009.
Edited: Wed August 06, 2014 at 6:37 PM by Chriskc
I installed a new low side valve from ackits and it leaked pretty much like the old one.
I made a steel cap sealed by an o-ring that screws in place of the original plastic cover and that stopped the leak permanently. Rather than evacuate the system and try another valve that was the best solution for me.
I installed new high and low ports. Then I evacuated to see if there were any leaks.
I evacuated twice. The 1st time I closed off the manifold valves and removed the manifold from the low port to verify the low port was not still leaking.
Second time I evacuated and pulled the manifold from the high port to verify the high side was not leaking. No leaks.
So now I've pulled the o tube and accumulator and I'm trying to find our how much oil to put in the accumulator before I install it.
I drained out 3 ounces of old oil.
Edited: Wed August 06, 2014 at 6:37 PM by Chriskc
The amount of oil is always a guess unless you flush clean and replace it all. This is especially true if someone has worked on the system before without flushing clean and replacing it all.
In 2009 shop put a new compressor in. 2011 they put an evaporator in. The copy of the 2011 work order just says "oil compressor".
Neither work order says anything about a flush though this was a very reputable shop that only does AC work.
I may just put the same amount in that I got out. Possibly an extra 1/2 ounce.
Edited: Wed August 06, 2014 at 7:31 PM by Chriskc
I put the same amount of oil back in the accumulator and installed a new o tube. Pulled a vacuum and it sat almost a day with no leak.
This calls for 32oz so I put 2 12oz cans and part of a 3rd 12oz can. While putting in the 3rd I periodically weighed it until 8 oz went in then closed it off. 12+12+8=32.
50 degrees at the vent. After a couple of minutes after finishing the freon the vent temp went to 70 and stayed there. I can rev the engine to 2k RMP and get to the lower 60's temps.
Checked the pressures:
At 2k rpm
Ambient Temp here is upper 80's with high humidity. Cooling fans are working.
Edited: Fri August 08, 2014 at 5:35 PM by Chriskc
Check that your low side gauge is zeroed. You should never see less than 20 psi low side on a variable compressor system.
Overall those pressures combined with a known full charge suggest that the evaporator should be quite cold. Are you sure it's not reheating the air? Cold at first then gets warm as the engine warms up suggests that.
Yes, gauges are zeroed. Getting about the same readings today.
The last few times I put the gauges on I noticed when I opened the manifold the low side gauge started at zero and went up
all the way around clockwise to zero and then up to 15 pounds. I'm thinking something is wrong with the gauges. This is
only the second time I've used them, cheapo Harbor Freight manifold.
Took the car out and I'm getting down to lower 40's and 50's depending on the weather. Only thing I notice is that it takes
5 or 10 minutes to reach maximum coldness while idling. I'm wondering if it would have been better to put in an adjustable o tube?
I'm still not sure what the initial problem was. I'm thinking that it was air in the system from the leaking port.
Both fans are working and come on. Shined a flashlight through the condenser and looks pretty clean.
Just a few bugs but very minor. Nothing restricting the air flow.
I checked it more than once since ambient temperature can give different readings. Thanks for letting me know my mistake. Last couple of times I did have the low manifold open with the yellow hose
hooked up. Amateur mistake/brain fart on my part although for my initial reading in the first post I did have it closed. Just checked it and pressures.Here they are:
Edited: Mon August 11, 2014 at 9:22 PM by Chriskc
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