WreckZ

Hey Everyone

For my first ever post I need to ask the question that has been bugging me since I got my truck . I drive a 2008 F-150 5.4L v8 Triton, hes my issue. Every once and a while I hear a knocking or tapping sound, it sounds like it is coming from behind the dash and not the engine bay. Thanks for your time.

08screwCA

Does it sound like uts coming from drivers side air vent closest to the right side of steering wheel?

07ford

My wife was complaining about a faint tapping/knocking in my 07...a quick listen and it turned out to be the cd changer trying cycle through the cds. Hahaha...wish they could all be that easy.

WreckZ

It's hard to say exactly but to me it sounds like ito coming. From behind the stereo. it actually Could be the vent you are suggesting. Any suggestions as to what it might be.

WreckZ

Did she hear the sound even when the stereo was off. The sound randomly comes and goes. And what was your resolution with the wife's cd changer.

FX4lyfe

Locate your blend door and mode doors, unplug them one at a time and see if that cures the noise. Sounds like a bad actuator on one of them to me.

08screwCA

There's a blend door actuator that is cheaper than doors or motor. Mine had that problem behind air vent/radio. Blend doors themselves throw a code dealership picks up on I think.