Compressor,TXV, or Scroll valve

[bobwan99]

Bought a used 2006 Ford Freestyle last winter from private one owner. I have cool air on highway with warm air in town. Previous owner had aftermarket compressor put on in 2013 and said it began acting up last summer. He had dye test and pressures checked and they added a small amount of refrigerant. No leaks. I just had a AC tech check the pressures. I saw readings. Ambient temp was 85 F with car warmed up and running. At 750 rpm idle with the AC set at 60 F on both driver and passenger side controls(it has dual controls) with fans blowing on high the low pressure side reading was 52 and high side was 100. Both abnormal.

At 2,100 rpm on interstate the air coming out of driver side front ducts was 72 degrees, passenger front ducts and rear ducts 82 degrees. After exiting highway and pulling over within 2-3 minutes at idle of 750 rpm duct air temp on driver was 82 and on the passenger and rear ducts it was 89 degrees.

I can hear compressor cycling. condenser coils are clean. I checked suction line and it was warmer than high side line coming out of compressor that goes to drier. Drier is same temp as high side line and normal to touch. If I increase temp settings to heater the fans blow hot air which makes me believe the blend actuator and door is ok. I believe it is either the scroll valve, the expansion valve, or the compressor as I have read that the drivers side vents are provided cold air before the passenger and rear vents. I can replace TXV and scroll valve much cheaper than the compressor as labor costs getting it off and on are pretty expensive due to its location Any thoughts as where to start will be appreciated.

[JohnHere]

The compressor on your vehicle is known for two issues: The control valve (sometimes called a "scroll valve") malfunctioning, and leakage of refrigerant/oil at the mating point of the two case halves.

If you can get under there with a strong light to take a look at the bottom of the compressor, check for the presence of fluorescent yellow-green dye and/or oil wetness. If you find either one or both, I would replace the compressor with a new OEM unit, not rebuilt. If it's dry down there, I would replace just the control valve.

In either case, you'll have to recover the refrigerant that's in there now (or have it done) to make the repairs. Then evacuate well and recharge to spec: All engines, with rear A/C -- 38 ounces of R-134a and 9 ounces of PAG-46. Doing that will also ensure that it is charged to the correct amount, which is very important.

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[DetroitAC]

You are just undercharged with refrigerant, take it to an A/C shop, quick and easy job to pull the charge and weigh in the correct charge.

I don't think it's your problem, but:
Extremely common issue with Visteon/Ford variable scrolls is a leaking control valve. The valve can be removed and flipped over, reinserted into the compressor, which turns the compressor into a fixed capacity scroll, and it will work great, well I guess it'll work as great as it can, scrolls are pretty weak at idle speeds.

I actually helped an A/C engineer friend of mine do this in my driveway years ago. He didn't want to take it to an outside shop and try to explain this, much easier to just get me to recover, he flipped it, evac and recharge. I think it's a two bolt football shaped steel piece on maybe the rear of the compressor. Kind of a tight squeeze for hands, but we did it without removing anything but that little cover.