Air conditioning issue

gselvamw

I have a 2004 Saturn VUE, 3.5 L, V6 (212 CI), AWD, with 164,000 miles that I purchased used in Michigan from a GM Dealer about a year back.
The air condition on this VUE works great as long as the vehicle is moving on the road. When in idle and parked, the cooling performance appear to get reduced and soon it will blow not so cold air until the vehicle start to move and gradually the performance will get better and perform well.
Is there anybody out there had this issue and if so how did you get it resolved?

Mr_Shiftright

You should check to see that your electric cooling fan is working. Have you noticed say, if you park overnight, or in the shade for a number of hours, that when you start up the AC works fine at idle? If so, then the cooling fan is where I'd look.

Other possibilities might be low refrigerant level or clogged up expansion valve.

gselvamw

I had this issue from the day I purchased the VUE 2013. So my assumption is that there is no refrigerant leak. When I first noticed the problem, Thinking that there may be a leak, I consulted a mechanics I’ve been using for about 35 years. He confirmed that there is no leak and the pressure is where it should be. He also quoted $400 to diagnose and fix. As I mentioned on my previous post. As long as I am driving, the A/C performs great even in the 90°F Florida weather. The performance appears to reduce while I wait at traffic signals or parked for an extended time which I seldom do. I was curious as to if anyone else experienced this issue. I never come across this issue in my past 55 years of driving various other vehicles including a 1957 Desoto.

thecardoc3

For $400, exactly what did they say needs repaired? Are the cooling fans not working correctly?

gselvamw

They said that they didn't know what needs to be done until they perform a complete diagnostics I just simply walked away from that situation. The cooling fan is working great at all four speed settings.

thecardoc3

When you say all four positions, that would most likely refer to the heater blower motor inside the car. The engine cooling fan that I asked about is under the hood next to the radiator. There are some that are two speed, some are fully variable, and of course some are single speed, but none that are four different speeds.

The biggest question is, how could you have a price when the system wasn't diagnosed yet? Was that an off the wall guess by someone? All too often shops get pressed to make a "guestimate". That is really a mistake on both the consumer for asking for a price right off the bat as well as the shops representative in providing one before enough is truly known about a given issue. That practice often leads to confusion and the person guessing the price usually get's to be wrong no matter what the outcome is. In this case it appears providing the guess without proof chased you away. Meanwhile the guess could easily have been too high making it look like it might be unaffordable and possibly like they were trying to take advantage of you, and yet it could have been too low which means it then would get adjusted back to the correct amount once the real price is calculated, again making them appear to have taken advantage of you in some perspectives.

Meanwhile there is still the fact that they couldn't tell what was wrong until diagnostics are performed. That is the only part of this event that is correct at this point. The appearance from the description is that the cooling fans might not be working correctly, that has yet to be proven or disproven.

gselvamw

Thanks for your input on this matter thecardoc3.
My statement regarding the four position fan was with respect to the evaporator fan behind the dashboard. I checked the condenser fan under the hood next to the radiator and it appears to be working fine. I had the VUE on idle for several minutes to check this and the fan appears to be fully variable. Wouldn’t the radiator/engine overheat if the condenser fan is not working properly specially in Florida’s hot weather?
I was given a written quote for the fix and I don’t believe it was an off the wall guess but I’m not sure. Since they were not able to tell me exactly what was wrong, I walked away from that situation. I used this auto repair shop in Michigan for over 35 years while the person who started the shop operated it. He got ill and retired with cancer and his son took over. Things went downhill from that time.

thecardoc3

The cooling fans are variable speed, controlled by the PCM based on the AC system high side pressure. The AC compressor is also a variable displacement design, and the system uses an "H" valve for its expansion valve. Proper testing of the system needs to be done with the AC set on Max (recirculate), high blower, full cold with the doors open. The tech needs to watch the gages on the AC machine while taking specific contact temperature measurements to fully evaluate the system. One thing the tech can do to help prove what is happening is to use a scan tool and command the cooling fans to run at high speed, or put a fan in front of the car to assist in ensuring good airflow through the condenser.

If tested this way and no problems are proven then it is plausible that the system is operating correctly depending on the ambient conditions. The difficult part however is all of the pressure to be the best price usually makes it unlikely you will find a shop/technician that tests this deeply for what starts out as a routine AC check. Not mentioned above is also the fact the refrigerant could be contaminated, so an identifier should be used to test it. Lots of shops simply recover, evacuate and recharge and they fox the car when a contamination issue was at play but since they neither own or use an identifier they end up not actually knowing what fixed the car. Some of the othetr more difficult issues that can present from time to time are excessive oil in the system, a failed compressor variable displacement control valve. There is even another condition more routinely associated with another manufacturer called black death where the compressor starts to fail and wear from the compressor piston rings and the cylinder walls mixes with the refrigerant oil and makes a black paste which coats the insides of the tubing and that creates an insulating layer between the refrigerant and the tubing in the heat exchangers.

gselvamw

Thanks for your input on this matter thecardoc3.
I purchased this vehicle used in 2013 with about 164K miles. There was couple of other issues (Not related to A/C) that I was trying to find answers to. I posted those issues on this forum under “Is there anybody out there had this rattling issue?” I thought I was posting them under “grinding noise in the mornings”. Anyway, as I mentioned on that post, I found a small shop in Cape Coral who gave me the proper diagnosis and fix for about 25% of what a GM dealer quoted with absurd incorrect diagnosis.
I took the VUE to this shop in Cape Coral and asked them to check the refrigerant pressures. After a test drive the mechanic came back checked and informed me that the high side of pressure was 150 psig and the low side of the pressure was 70 psig. He said that the pressures should have been 200 and 35 respectively. He then presented me with a written quote of $1800.00 for what he claimed to be the proper way of fixing this A/C Issue. He said that the compressor is shot and needs to be replaced along with the dryer and expansion and proceeded to pointed to a small 1/8” dent at the bottom of the condenser coil and said that the quote included replacing the condenser coil as well even though it is not leaking and never leaked. Ever since I discovered the A/C issue I have been monitoring the properties of the discharge air at maximum A/C, max air flow and with recirculation. The worst case scenario at an ambient temperature of 90°F, while moving, it reached 57°F and 45% RH. While waiting at a traffic light, the temperature and humidity increased slowly and gradually. I was getting close to these readings consistently.
Since the A/C system is performing fine while vehicle is on the move, I guess I’ll hold off until I discover the real reason for this issue or wait until the system fails completely before considering any further repair approach.