[drrohle]

2009 Tacoma, 32,000 miles.
Last week I noticed that when I have the AC on with the blower set around med-high I hear a ticking/rattling noise coming from the vent thats on the left side of the radio. The noise goes away when turning the temp from cool to hot and only makes noise when putting air through the upper vents.

I took out the cabin filter (which is new) and listened to the blower motor and could hear no noise or rattling so I'm pretty sure it's not the blower asy. the frequency of the noise changes with the speed setting of the blower though.

I'm almost thinking that the diverter gate (from hot to cold) is flapping around in there but don't know where to look or how to get to it.

 

[RTFM]

The diverter under the dash are seriously buried, a major shop project to go after.

I would wonder more about something loose inside the duct, like a leaf, piece of tape, etc, that may have gotten in last time the cabin filter was changed.

 

[drrohle]

The diverter under the dash are seriously buried, a major shop project to go after.

I would wonder more about something loose inside the duct, like a leaf, piece of tape, etc, that may have gotten in last time the cabin filter was changed.

It did start about a week after I had the pickup serviced, which included changing the cabin air filter. I was gonna take it back in today but (on this day) the noise is gone and I'm not going to waste their time and my money chasing down a phantom noise. Guess I'll wait until it becomes more consistent or goes away entirely.