2005 Mitsubishi Galant A/C Noise

2005 MITSUBISHI GALANT
100,000 MILES • 4 CYL • 2WD • AUTOMATIC
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RPESPINEL
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  • 2 POSTS
Hello,
I took my Galant to the shop because the A/C was not blowing cold air. The shop replaced the evaporator coil inside the dashboard. A/C works fine for the exception the your hear a "discharging air sound" coming from the dashboard about every 3-5 minutes. This sound I never heard before the repair or when it was in woking order. I took it back to the shop and they told me the sound was normal and I had to live with it.
Any thoughts.....
Feb 19, 2010 at 8:19 AM
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KHLOW2008
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Hi rpespinel,

Thank you for the donation.

To a certain extent, such noise do exist in AC systems and some cannot be resolved. It usually is caused by the expansion valve. Was it replaced during the replacement of the evaporator and if yes, was it OEM standard?
Feb 19, 2010 at 8:43 AM
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RPESPINEL
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[quote:da73576d55="KHLow2008"]Hi rpespinel,

Thank you for the donation.

To a certain extent, such noise do exist in AC systems and some cannot be resolved. It usually is caused by the expansion valve. Was it replaced during the replacement of the evaporator and if yes, was it OEM standard?[/quote:da73576d55]

The expansion valve was not replaced. Do you think it would have made a difference? I paid a good chunk of change in labor due to them taking the dashboard out.
thanks for your responses
Feb 19, 2010 at 7:25 PM
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KHLOW2008
  • CAR REPAIR CONTRIBUTOR
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Replacing the expansion valve might have made a diffference but there are other possible concerns.

Possible causes for the noise.

Whistling type of noise would be due to the evaporator, some evaporators produce such noises even though it could be OEM. This cannot be resolved as is it a design fault and you would have to get another one, maybe from a different supplier.

If the noise is gurgling or slightly hissing type :

1. Faulty expansion valve. If the system was discharged too fast or incorrectly it would cause the expansion to fail. However this could also be due to the valve failing when the system leaked. Replacement wuold resolve the problem.

For items 2 and 3, they can be done without any removal of components and you could give it a try.

2. Insufficient gas in system. When insufficient gas is n system, the gurgling would be noticeable when the compressor cycles on and off. Recheck the gas pressure.

3. Improper vacumn before refilling of gas. When insufficient or improper vacumning of syatem was carried out, air could be trapped in system and this would cause the noise. Get the shop to recover the gas and revacumn the system before refilling the gas and see if it helps.
Feb 19, 2010 at 10:41 PM