Air conditioning noise

2017 NISSAN SENTRA
41,000 MILES • 4WD • AUTOMATIC
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UHJARAMILLO
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My car has recently started to make a rattling noise only when I first turn on the A/C, it goes on for a few seconds at a time and stops then does it again for a couple of minutes. My A/C still blows out cold and hot air. (Sorry for the awkward feet showing)

Clicking noise is me turning on and off the A/C
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Jun 24, 2020 at 7:03 PM
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JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
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Hi,

When the A/C turns on, there is a heavy load placed on the engine. Often times, a loose heat shield on the vehicle's exhaust system will do it. I attached an exploded view of the exhaust and circled two heat shields so you have an understanding what I referring to.

What to do is this. Take a rubber mallet and tap on the exhaust system to see if you can reproduce the sound. If you can, then have a helper tap while you locate where it's coming from.

Let me know what you find. Also, pay attention to see if the sound seems to come from under the hood or under the vehicle. I noted that it seems to make the noise when the A/C compressor is turning on.

I will watch for your reply.

Joe
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Jun 24, 2020 at 8:08 PM
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UHJARAMILLO
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It seems to be coming from the hood by the middle/ drivers side, I will add a video although the noise is faint to see if it helps (sorry for showing my feet!) I will try that out tomorrow morning and let you know!
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Jun 24, 2020 at 8:22 PM
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JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
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Hi,

I'm having a hard time hearing it. I do hear something, but I'm not completely sure. To me it almost sounds like an air flow restriction. Have you ever replaced the cabin air filter? Here is a link that explains how it's done. Your's is behind the glove box.

https://www.2carpros.com/articles/how-to-change-an-air-cabin-filter

Let me know.

Joe
Jun 24, 2020 at 9:43 PM