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  1. #1
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    Default Air Conditioning (A/C) Runs Warm, then Cold...

    Please help! I have a 2011 XC60 R-Design and when I turn the AC on, it starts off warm, then after about five to ten minutes it gets cold. Once the system has run for awhile it sometimes goes back to blowing warm.

    I have checked the freon level and it is good.

    Thank you!

  2. #2
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    Quote Originally Posted by terand_1 View Post
    Please help! I have a 2011 XC60 R-Design and when I turn the AC on, it starts off warm, then after about five to ten minutes it gets cold. Once the system has run for awhile it sometimes goes back to blowing warm.

    I have checked the freon level and it is good.

    Thank you!
    You may have a bad control valve in the compressor. It controls the compressor displacement. (changes the angle of the swashplate) Check your return pipe at the compressor (the large one) It should be very cold, (the small pipe can be very HOT!) If it is not cold or takes a long time to get cold - the valve may be bad.

    Depending on the VIN a 31305844 and 31436166 has solved that problem many times. Not hard to replace but the freon has to be removed first.

  3. #3
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    VIN is: YV4902DZ4B2185153

    Would a bad Compressor Control Valve appear on a full vehicle computer scan?

  4. #4
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    Quote Originally Posted by terand_1 View Post
    Valve appear on a full vehicle computer scan?
    What is a "Full vehicle computer scan"???????????????

    VIDA (the factory VOLVO tool, either a subscription or the stolen e bay system) is probably the only scan tool that can report the duty cycle or percentage (it's been awhile since I have tested a compressor control valve).

    I don't think a generic "Full vehicle computer scan" will do anything but remove - let me guess - $29.95 from your wallet! Wait, you're in California - maybe $69.95+ stolen from you.

    Please find someone who can diagnose this properly or just pay someone $1200-1500 to replace your compressor and it will be fixed.

  5. #5
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    Quote Originally Posted by hoonk View Post
    What is a "Full vehicle computer scan"???????????????

    VIDA (the factory VOLVO tool, either a subscription or the stolen e bay system) is probably the only scan tool that can report the duty cycle or percentage (it's been awhile since I have tested a compressor control valve).

    I don't think a generic "Full vehicle computer scan" will do anything but remove - let me guess - $29.95 from your wallet! Wait, you're in California - maybe $69.95+ stolen from you.

    Please find someone who can diagnose this properly or just pay someone $1200-1500 to replace your compressor and it will be fixed.
    I am paying a mechanic $65 this Friday to diagnose. I would hate to spend $1500 (this is what mechanics are quoting to extract, replace compressor, and refill system) to find out the issue isn't the compressor and was simply a Failing AC Pressure Switch that only costs $175 (including labor) to replace. (https://forums.swedespeed.com/#/topics/604211)

    Also, the vehicle makes kind of a humming noise whenever the AC is on, this is the first car I have ever heard this in. Also, the other day I was in stop and go traffic on the freeway, it was 105 degrees outside, and the AC was blowing warm air (a mechanic thought it might be a bad fan), I'm wondering if the AC system is controlled by a thermostat? Maybe a bad relay switch (I'm not sure how these systems are controlled)?

    Will know more Friday.

  6. #6
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    Quote Originally Posted by terand_1 View Post
    I am paying a mechanic $65 this Friday to diagnose.


    Also, the vehicle makes kind of a humming noise whenever the AC is on,

    the other day I was in stop and go traffic on the freeway, it was 105 degrees outside, and the AC was blowing warm air (a mechanic thought it might be a bad fan),

    I'm wondering if the AC system is controlled by a thermostat? Maybe a bad relay switch (I'm not sure how these systems are controlled)?
    I would find a shop that knows what these valves are and has replaced them before. Variable displacement compressors are used in many brands of cars. And if a shop is not familiar with them they will be reluctant to just replace the valve - because they know the compressor will fix it.

    The humming sound you are hearing could be a common noise Volvo identified and solved under warranty. It involved replacement of the low side hose.

    The mechanic that thought it was a fan - Is that the one that is "diagnosing" your car Friday?

    The ac compressor runs all the time generating cold freon. The variable displacement reduces the load, the amount of power needed to spin the compressor when the control unit thinks is should. Hot water for the heater is flowing all the time through the heater core. Air temp is controlled by blend doors, mixing hot air from the heater (if needed) with cold air from the ac evaporator to produce your desired temp.

    If your ac is not cold - the first step is to see if the compressor is spinning. The electric clutch on the front of the compressor is visible, and can be easily determined if the center of the clutch is spinning with the outer pulley. Clutches can go bad (on the 3.2 clutch there is a "dampening ring" inside that can come loose and prevent the clutch from operating. Have only seen that "ring" on a 3.2 compressor)

    Other things can keep the compressor from coming on - If the radiator fan does not work, the compressor won't run. If thermostat is broken (common in 3.2s) the engine will run hot and since there is no temp gauge (some cars) you won't know it until it gets really hot.

    You mentioned earlier you "had the freon level checked". Freon is put in by weight. Modern ac machines can measure the weight of the freon in a car WHEN YOU TAKE IT OUT. In other words you can't tell exactly how much is in the system without taking it out and putting the correct amount back in. However, if the return pipe is cold, and the running pressures are normal, it MIGHT have the correct amount of freon. If someone "checked your freon" - they may have simply hooked up a gauge to see if there was pressure. If the pressures were normal when the car was running, the low side pipe would be cold. (and if blend doors and everything else were working properly - cold air in the car) How was it determined your freon level was correct?
    Last edited by hoonk; 09-18-2019 at 09:24 AM.

  7. #7
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    Quote Originally Posted by hoonk View Post
    I would find a shop that knows what these valves are and has replaced them before. Variable displacement compressors are used in many brands of cars. And if a shop is not familiar with them they will be reluctant to just replace the valve - because they know the compressor will fix it...
    I am taking the vehicle to an Air Conditioning Specialist shop Friday. The "fan" suggested mechanic was someone else. I, personally, did the Freon pressure/level check with A/C Pro (as I have done in the past with most of my vehicles). They will also check the pressure in the system (not sure if they will "take it out").

    I have had multiple mechanics say the AC system needs the freon extracted and then refilled...yet the research I have done says that freon doesn't go bad, and should only need refilling if there is a leak...and the Air Conditioning Specialist Mechanic agrees with this statement.

    I checked for open recalls for the vehicle and there were none. I will take the car to the dealer and ask them about the "The humming sound your hearing could be a common noise Volvo identified and solved under warranty. It involved replacement of the low side hose." Thank you!

  8. #8
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    Quote Originally Posted by terand_1 View Post
    They will also check the pressure in the system (not sure if they will "take it out").

    I have had multiple mechanics say the AC system needs the freon extracted and then refilled...yet the research I have done says that freon doesn't go bad, and should only need refilling if there is a leak...and the Air Conditioning Specialist Mechanic agrees with this statement.

    I checked for open recalls for the vehicle and there were none. I will take the car to the dealer and ask them about the "The humming sound your hearing could be a common noise Volvo identified and solved under warranty. It involved replacement of the low side hose." Thank you!
    Techs suggest evacuating and recharging systems sometimes as a first step in solving the ac not cold complaint. (after making sure the compressor is coming on and other basic stuff) Easy to do, hook up and program the machine, they can bill time working on another car during the evac and recharge, come back 45 minutes later, and it's cold/fixed. On some cars a few ounces over or undercharged and the system will not cool properly. Also, poor charging methods get air introduced into the system sometimes, which even if the proper weight of refrigerant is installed the system, it still won't blow cold air. You are correct - freon does not go bad, but it does get contaminated and the charging stations extract, clean and recycle the freon. The customer usually ends up buying "new" freon even if your system was full. Got to pay for the ~$5000 ac machine

    There was not a recall on the noisy hose - customer had to complain (during the warranty period) for it to be replaced.

  9. #9
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    Quote Originally Posted by hoonk View Post
    Techs suggest evacuating and recharging systems sometimes as a first step in solving the ac not cold complaint. (after making sure the compressor is coming on and other basic stuff) Easy to do, hook up and program the machine, they can bill time working on another car during the evac and recharge, come back 45 minutes later, and it's cold/fixed. On some cars a few ounces over or undercharged and the system will not cool properly. Also, poor charging methods get air introduced into the system sometimes, which even if the proper weight of refrigerant is installed the system, it still won't blow cold air. You are correct - freon does not go bad, but it does get contaminated and the charging stations extract, clean and recycle the freon. The customer usually ends up buying "new" freon even if your system was full. Got to pay for the ~$5000 ac machine

    There was not a recall on the noisy hose - customer had to complain (during the warranty period) for it to be replaced.
    Got it.

    Have you heard of overriding the AC Pressure Switch?

    Also, vaccuming out the system would make sense if there was a blockage of some sort, but the question remains, where would the blockage come from? Broken seals/rubber?
    Last edited by terand_1; 09-18-2019 at 10:33 AM.

  10. #10
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    Quote Originally Posted by terand_1 View Post
    Have you heard of overriding the AC Pressure Switch?

    Also, vaccuming out the system would make sense if there was a blockage of some sort, but the question remains, where would the blockage come from? Broken seals/rubber?

    Most ac systems have both a low and high pressure cutoff switch - don't think that's what you are asking about though.

    If you mean overriding the compressor displacement valve? No it's not an on/off thing. Your ac compressor is a little radial ~6 cylinder 2 cycle pump. 6 little pistons, 3 on each side of the swash plate, suck in and compress the refrigerant, reed valves control the intake and exhaust. The swash plate controls the stroke of the pistons. The displacement valve allows pressurized freon to change the angle of the swash plate making a longer or shorter stroke. Long stroke= higher pressure/more cold air, short stroke =lower pressure/less cold air. Google swash plate, it's interesting technology.

    After recovering the refrigerant, evacuating the system (using a strong vacuum pump) is the next step. The purpose is to remove any moisture from the system. Any moisture in the system can freeze and block the flow of refrigerant. Also mixes with the refrigerant oil and creates corrosion inside the system. Water boils near room temperature under a strong vacuum - so usually at least 20 minutes under vacuum to eliminate any moisture.

    There will not be a blockage in the system that Vacuuming (evacuating) will help with. Yes under rare circumstances a compressor can disintegrate internally and spread metal shaving all through the system. If that happens it's almost impossible to get all that shredded metal out - you end up replacing many or all of the ac components, compressor, condenser, evaporator, expansion valve, etc.

    That very rarely happens.

    There are only two moving parts in the ac system - the compressor and the expansion valve which regulates the flow of refrigerant.
    The expansion valve holds the freon back and sprays it into the evaporator causing it to expand rapidly, the freon gets very cold when it expands. Expansion valves can clog, and I have replaced many over the years - but not on a Volvo made after 1990. Pressures in the system help diagnose expansion valves. System pressures don't really help diagnose compressor control valves. Talking to the CCM (climate control module) and the CEM using VIDA or a compatible scan tool (if one exists) is a good way to find out what signal is going to the valve.

    I would be willing to bet you simply have a bad compressor control valve.

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