Well in a '06 with HK sound system when i listen to CD,RADIO I have no issue but when I go to AUX in I get a odd noise (think odd sounds the aliens sent from the movie Contact, but mine doesn't count prime numbers). I've replaced both the AUX cable that goes from the head unit to the glovebox and the head-unit itself. This happens with iPhone4 and iPod classic.

 

Are you connecting the iPod to external power (cigarette lighter), or just run them from their battery?

 

Do a search, I remember reading a post that solved this this issue. something about installing a filter. SImple fix. Do a search. I cant right now but it IS solved in another thread.

 

https://www.northamericanmotoring.co...ut-issues.html

one of many posts

seach 'ground loop'

 

Well I'm not charging either device while playing. If fact the noise happens even before the iPod or iPhone is even connected.