Weird fan noise coming from the back of our Macan.

[WillyDaP]

We have an absolutely strange noise coming from the back of our Macan S that for awhile we thought was the rear AC vents. Closing the rear vents and turning off the AC does not stop the noise. Leaving the Macan running and opening the rear hatch I can not hear a thing, but getting back in it is still noticeable. Bizarre , because one would think if it was a fuel pump you could hear it outside the car or inside the rear hatch. The AC is off , so that makes it more puzzling. If we let the car sit for a bit the noise is often not there when we start the car again. It comes and goes , but I can't think of any other motor running on its own , including the rear wiper fluid squirter ( full of fluid and nothing is coming out anyway). Heck we even turned off the radio, so wondering if anyone else encountered this weird fan like noise in the back of their Macan?

Vehicle in question is a 2020 Macan S

[dr bob]

On a completely different car, there are "setting motor" and "blend door" actuators driven by small motors as part of the climate control system. To test to see of those are the sources of your noise, swap the mode if you can separately, and the temp setpoint above and below ambient cabin temp to see if the noise stops. The systems generally don't do a lot of adjusting unless/until coolant temp are up high enough to actually contribute heat .and. the AC side has run long enough to pump some system heat out of the cabin side of the system. At the same time, the rear fans usually stay off or very low following initial engine start, only speeding up after the system is able to move heat around.

So I won't assume that a fan isn't running unless the fuse is removed. On the setting and blend door motors, moving the system mode and temperature selections will cause those motors to move damper doors in the subject air box. Stick your ears near that air box to hear them working and more importantly stopping once they reach target position. A sticking mechanism can leave the motors trying to move them. Engine running and at normal temp of course. This diagnosis takes just a few non-invasive minutes except for pulling and replacing the fan fuse.

[Tom]

On a completely different car, there are "setting motor" and "blend door" actuators driven by small motors as part of the climate control system. To test to see of those are the sources of your noise, swap the mode if you can separately, and the temp setpoint above and below ambient cabin temp to see if the noise stops. The systems generally don't do a lot of adjusting unless/until coolant temp are up high enough to actually contribute heat .and. the AC side has run long enough to pump some system heat out of the cabin side of the system. At the same time, the rear fans usually stay off or very low following initial engine start, only speeding up after the system is able to move heat around.

So I won't assume that a fan isn't running unless the fuse is removed. On the setting and blend door motors, moving the system mode and temperature selections will cause those motors to move damper doors in the subject air box. Stick your ears near that air box to hear them working and more importantly stopping once they reach target position. A sticking mechanism can leave the motors trying to move them. Engine running and at normal temp of course. This diagnosis takes just a few non-invasive minutes except for pulling and replacing the fan fuse.

That was my first thought too -- i.e., that the dash controls may not be turning everything off. Based on my Track Nanny R&D, I've learned that some of the user-controls are more like suggestions to computers that actually turn stuff on and off. Does it make the noise when the motor is off? Transmissions and fluids (fuel, coolant) can make some funky noises that you can hear inside but not outside.

[WillyDaP]

Thanks gentleman and those are good areas to check as we ( my wife and I ) have only noticed it recently. It does not continue when the engine is off though, so that is one area that helps define some of the problem - appreciate the suggestions.

[Rusty Rotors]

Long shot but unsure of 'where' you say the noise is coming from. Inside or outside of the car? My long shot is that maybe you have the seat cooling fans on? When mine are on I hear a 'fan' type noise coming from behind and below the drivers seat. Now that I know what it is it seams quite obviously the seat cooling fans.

[WillyDaP]

Interesting thought as we have not heard the noise for awhile and we haven't had the seats on , but we might have hit the button on one seat. Like many noises we can not get it to happen again so no need to take it into the shop, ha.

Appreciate the thought and we will turn on the seats on the next drive just to verify.