Car vibration when the A/C is turned on?

2019 JEEP GRAND CHEROKEE
53,000 MILES • 3.6L • V6 • 4WD • AUTOMATIC
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HASSANMAHMOOD
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  • 18 POSTS
Hello, glad to be helped,

My vehicle starts vibrating, few seconds after I turn the A/C on.
So, I heard that the cooling fan may be the cause for that, I had a video recorded and might help diagnosing that.
I am in doubt whether this is the cause or something else.
Video (Click to enlarge)
Attached Media
Jul 26, 2024 at 3:43 PM
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JACOBANDNICKOLAS
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Hi,

Is there play in the fan blade? In other words, can you wiggle it on its mount? Also, that really doesn't look too out of the ordinary. How low do the engine RPM's get when the A/C is on, and you notice the vibration?

Do me a favor. Start the engine and turn on the A/C until you feel the vibration. Increase the engine RPMs slightly (approximately 1,500 RPMs) and see if the vibration stops.

Let me know what you find.

Joe
Jul 28, 2024 at 6:56 PM
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HASSANMAHMOOD
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sir, the vibrations end even at 1,000 RPMs, but related to what you said about if the fan wiggles around its mount, I attached a video sir.
thanks again.
Video (Click to enlarge)
Attached Media
Jul 29, 2024 at 3:22 AM
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JACOBANDNICKOLAS
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Hi,

The movement in the fan seems okay and not excessive. When the fan is on and you feel the vibration, how low are the engine RPMs? If the vibration goes away at 1,000 RPMs, that leads me to think the engine idle speed is too low when the load from the A/C compressor is added. If it was the fan itself causing the vibration, it would continue even after 1,000 RPMs.

Let me know.

Joe

Jul 29, 2024 at 10:37 AM
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HASSANMAHMOOD
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sir, I think it does not increase on ac start!!!
I have a video recorded for that..
Video (Click to enlarge)
Attached Media
Jul 29, 2024 at 3:01 PM
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JACOBANDNICKOLAS
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Hi,

The engine speed appears to be fine. Do me a favor. Check to make sure nothing is loose. Check the mounting bolts on the A/C compressor itself.

Let me know.

Joe
Jul 30, 2024 at 11:46 AM
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HASSANMAHMOOD
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sir, the bolts are tight already ...I made sure of that ..
Aug 2, 2024 at 2:24 PM
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STRAILER
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I see you spinning the fan which looks okay from this angle, but I have seen a piece of plastic break from the fan blade which will cause it to be off balance. Also, if the A/C system is over charged or has too much compressor oil in it the system will vibrate, let's go over this video to see what the pressures should be:

https://youtu.be/4EqdrBVb0sY?si=kw5WoPtRGFs6y3XH

Check out the images (below). Please upload pictures or videos in your response of any problems so we can see what to help you with.

Aug 3, 2024 at 6:01 PM