Hey all,

I've searched but could not find much information in regards to an issue I've been experiencing.

I have 16 F54 S that has about ~35k miles on it at the moment.
The car has been maintained properly and drives perfectly fine.. EXCEPT for when you are sitting at a stop light or at a parking lot with engine fully warmed up.

After a few minutes of idling, there comes, what sounds like to be high speed fan kicks on and the car will begin to vibrate in a very consistent in a rhythmic fashion "Brrr - Pause - Brrr - Pause - Brrr - Pause - Brrr"....

At first, I thought the car was actually misfiring as the vibration was evident through the seat and with the sound.

But as soon as the fan slows down and turns off, the car will idle smoothly.

I searched around but could not find thread on similar issue, if anyone can chime in and tip me on what is actually wrong with the car, it would be much appreciated!

Thank you all in advance-

 

It may be a bad bearing in the fan itself.
Edit:

You may want to disconnect battery (safety) then see if fan shaft has any bearing play, also closely inspect fan blades for damage. Could be out of balance.

 

Check your passenger side motor mount. Though it does not link directly to your fan, if there's a big enough tear, you might get resonance vibration if the frequency of the movement matches up.

 

Hey all, I will check the two items mentioned above and see if I can notice anything at fault!

Thanks a lot guys

 

Did you find a solution for your issue? I think I do feel car(F55 MCS) vibrate in a rhythm when I turn on AC, car is at a stop light and I think fan also kicks in. When I turn off AC or switch off the fan dial, then vibration goes away. It isn't a lot but I can feel it in the steering wheel mostly.

Here is a service manual which shows some adjustment but seems complicated: https://www.newtis.info/tisv2/a/en/f...ats/1VnYvvf3Wb