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A/C Compressor buzzing noise.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by MichaelGol, Apr 7, 2020.

  1. MichaelGol

    MichaelGol New Member

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    Hello!

    A little info about the car first, it's a 2008 w/ 189k miles. Now the problem, So as the days are starting to become warmer the A/C will be something that is of use. But, i'm having a problem, this is how it goes in sequence; Press the power button, Fans kick on and starting blowing air, after that I hear a buzzing noise from the compressor along with a vibrating. This happens roughly 3/4 times and last about 5 seconds each time. After it goes through its routine, nothing happens, the fans only continue to blow hot and the compressor is not on.

    Now, what I'm thinking, somehow the compressor is siezed, how could this happen is a mystery to me. I am hoping this is a common effect cause by a failing/failed compressor, so I know what i'm dealing with, I am also hoping this might be one of those things with an easy fix.

    Thanks in advance.
     
  2. dolj

    dolj Senior Member

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    Have you or anybody "topped up" the 134a (a/c refrigerant) at any time?

    It may have the incorrect amount of refrigerant – either too much (from a top-up) or too little (from a slow leak). You probably need the system diagnosed by a fully qualified A/C technician who is a member of MACS (Mobile Air-Conditioning Society).

    At the very least you need the system evacuated and the properly measured amount (by weight) of R134a refrigerant (and correct amount of ND-11 oil) added back. If your compressor is toast, you will need to replace that too, but do that after ensuring the correct amount of refrigerant is in the system.

    Take note, the only way to guarantee that the charge is correct is by vacuuming out the whole system and recharging it to the factory specified amount.
     
    #2 dolj, Apr 8, 2020
    Last edited: Apr 8, 2020
  3. MichaelGol

    MichaelGol New Member

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    Ok, follow up time.

    I found a leak from the low pressure valve. I replaced the valve. I proceeded to add R134a and it did not take long for the system to reach a safe PSI, but I am sure the correct amount has not been added. I am assuming as you stated I need to create a vacuum on the system first in order to add the correct amount of refrigerant. If that is true will it be impossible to fill the system to what it need to be?
     
  4. MichaelGol

    MichaelGol New Member

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    I went ahead to complete the recharge of the system, I did the following; pulled a vacuum/checked for leaks, ran the vacuum pump for 30min. Now this is where I was having a problem, As I was adding a can of R134a 12oz, I was only able to add roughly 2/3 of the can before the PSI reached 60. I was not able to add anymore and the AC did not turn on. I am definitely going to need some help with this one.
     
  5. MichaelGol

    MichaelGol New Member

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    Hoping you might be able to give a little more assistance.
     
  6. dolj

    dolj Senior Member

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    The best idea would be to use the advanced search (click on the "More..." button) and find posts by "lech auto air conditionin". He discusses this subject.
     
  7. MichaelGol

    MichaelGol New Member

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    Here is the quick video of what is happening.