Single pop noise when starting the car

2020 HONDA CIVIC
11,000 MILES • 4 CYL • 2WD • AUTOMATIC
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STEVENMILLER404
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If this happened before I never noticed it. When I start my car, I hear a single fairly quite hollow pop or knock. It seems to come from the passenger side behind/below the glove compartment. It only makes the pop/knock once right when I first start the car. It does it weather the heat is switched on or off before I start the car. I just want to make sure this is normal or nothing serious, again, if it made this noise before I never noticed it. Also, it has just gotten cold (in the 30’s Fahrenheit) here the last couple days.

Thanks,
Steven M
Dec 8, 2021 at 12:53 PM
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SQM
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Hello,

This could possibly be the blend door actuator moving the door and it could be slightly misaligned and popping against another part.
Have you heard this noise before in warmer temperature?
Can you upload a video of the sound?

If it is a misaligned component or a loose component, it is possible for it to get worse over time.

As your vehicle should be under factory warranty, it would be good idea to visit the dealership and have them take a look at it and fix if necessary.

Please let me know of any questions.
Thank you.
Dec 8, 2021 at 8:36 PM
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STEVENMILLER404
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Thank you for the reply. I will try and get a sound clip of the noise after work. I have not heard it in warm weather, but again, I just heard it for the first-time couple days ago. However, I have noticed for a while now that the vents flaps seem to continue to move or make a noise even after the air or heat is turned off…kind of like a swishing/click noise. If it is the actuator, how bad could it get? Or what’s the worst-case scenario if it keeps getting worse before I have a chance to get it looked at? And how urgent is it to get checked out?
Thanks.
Dec 9, 2021 at 5:39 AM
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SQM
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The actuator is located behind the dash and will require removal of few components to get to.
What could happen is that the actuator can get stuck in one position, like to the cold side and then you will have no heat coming out.
Dec 9, 2021 at 9:30 AM
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STEVENMILLER404
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I tried to get a recording of the sound but it's not loud enough for the recording to pick it up.
Dec 10, 2021 at 5:14 AM
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SQM
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Got it.
Well, it is likely on of the air door. As this is still a new vehicle under warranty, your best option would be to just call the dealer and see what they say. It should be covered under warranty.
Dec 10, 2021 at 9:45 AM