Lately when I start my 07 4.7 4runner I get a faint clicking sound, sounds just like a sewing machine somewhere in the dash. Kind of sounds like it is coming from under the radio. It goes away about 5 minutes after driving, and seems to make the sound especially when the 4runner has been sitting for a while. Any ideas what it could be?
When sitting in park or rolling?
My 97 Tacoma gets a sound like that on cold mornings when rolling. If I get up to highway speeds it can turn into a full on scream! I tracked it back to the speedo cable behind an under the dash.
Probably a blend door on your AC or Heater distributing air. They make noise as they wear out. Adjust the temp up and down and see if the noise changes or goes away.
Does the noise stop if you turn off the A/C fan? If so, check that nothing has gotten into the fan (it's behind the cabin fliter IIRC). Somehow a damn walnut got into mine.