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AC on passenger side is blowing warmer and hissing sound on start

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Old Jun 20, 2025 | 05:40 PM
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AC on passenger side is blowing warmer and hissing sound on start

Upon starting the car I get about 3-5 seconds of hissing from the ac and the 2 vents closest to the passenger side are blowing warmer air. Upon researching a bit I am coming to possible diagnosis of a hose leak that would need to be replaced and to recharge all lines with refrigerant. I am sure this has come before if anybody has to a link to prior thread and problem solved. Is this something I can check myself before bringing it to the shop? Any help is greatly appreciated. Thanks.
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Old Jun 21, 2025 | 02:55 AM
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Originally Posted by lieu
Upon starting the car I get about 3-5 seconds of hissing from the ac and the 2 vents closest to the passenger side are blowing warmer air. Upon researching a bit I am coming to possible diagnosis of a hose leak that would need to be replaced and to recharge all lines with refrigerant. I am sure this has come before if anybody has to a link to prior thread and problem solved. Is this something I can check myself before bringing it to the shop? Any help is greatly appreciated. Thanks.
Need a specialist shop to inject Freon with uv dye.
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Old Jun 26, 2025 | 08:18 PM
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How do you run the onboard ac diagnosis to get values and any errors? Have tried all button combinations and nothing is showing.
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Old Jun 27, 2025 | 11:54 AM
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W205 2015
Check for freon gaz and before you refill you need to check that there is no leak
Worse part is the a/c compressor but start with freon gaz

Last edited by Andy74; Jun 27, 2025 at 11:55 AM.
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Old Jun 28, 2025 | 01:16 AM
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It does seem like it will eventually leak over the years by intention, I came across a thread with the whitepaper showing it will leak a certain amount in 10 years, this is intentional, I think it was because of something along the lines of protecting and lubricating the seals.
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Old Jun 28, 2025 | 11:06 AM
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anybody had this problem and it was fized with a recharge of r134a refrigerant? figure that is the first thing to do to see if it fixes the problem.
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