Air conditioning knocking noise
 

Yesterday after a 100 mile drive, I started the car up and the air conditioner made a loud clicking or knocking noise. It would stop when I turned off the AC. It was not speed or fan related. Weird. Finally it stopped after I turned the AC on and off about 10 times. Has this ever happened to anyone?

Check your in-cabin air filter behind the glove box. It may have come slightly unseated and the fan may be hitting it causing the clicking.

I'm having this EXACT same problem. I did change my air cabin filter a few weeks ago with a non-nissan filter but it was very non-eventfull until now. When i turn on the fan I don't have the problem. As soon as I turn on the AC, it starts making the clunking/knocking noise in the glove box area. Should I bring the car to the dealer for warranty repair. I can't understand how the cabin filter could cause this since the fan running full speed has no issues.

I know this thread is 8 years old, but I've developed exactly the same problem with my 2016 car.

When the air conditioning is on 'recirculate' I get a loud knocking noise coming from inside the centre of the dashboard. It seems to be a fan hitting something.

When I turn 'recirculate' off, the noise stops.

Could a fan be hitting some kind of flap? Did anyone find out what causes this knocking noise?

I think I remember reading about there being some kind of sealant/gasket material that could come loose and cause a knocking sound inside the ductwork. Not much to go on but maybe it will help narrow your search.

Thank you for your help, SouthArk. I suppose I should have posted a link to this short video I shot when the issue first occurred. It does sound very much like a 'plastic on plastic' noise.

Anybody else have any thoughts on the problem?

https://www.youtube.com/watch?v=e2R315YoS1k

Sounds like one of the actuators(mode door,blend door)are slipping.Very common problem on GM cars.

Thanks. Is that something I could access and repair myself?

Never done any on a Z but they shouldn't be too hard to replace seeing that ALLDATA only shows about an hour to replace anyone of them.:ugh2:

:iagree:

The FSM should have the R&R procedures. That will give you some idea of how difficult the job is. Link in my sig.

Fixed it!

Last night I removed the glove box and its surrounds (7 screws - easy job if you've got a very long screwdriver), then took the cabin air filter out. I reckon the most likely cause was the air filter becoming dislodged a bit (it can move around inside a housing that seems way too big) and stopping the a/c cowling from moving to its 'shut' position properly. The cabin air filter was a bit squashed on the left hand side.



Anyhow, the noise has stopped and I don't have to pay a mechanic a hundred pounds (UK) for something that took 15 minutes to sort out!



edit: sorry, I should have credited beachguard for giving me the idea. Thanks mate.




...oh, I took the precaution of turning the air filter 180 degrees before replacing it.