When I get the 7 above 3k, I hear a VERY faint ringing in the car, any ideas?

 

Mabey your amp to the stereo are to close to the battery ? Mine rings but extremely bad and increases with rpms

 

i know EXACTLY what your talking about. Well, this is in my dad's Chevy truck acutally. It's got no tacho... BUT whenever it hits 70mph, you hear a ringing noise and its gone after its past 70. So i think it is hitting a certain RPM and making that noise. Sorry, but i dont know why it does that.

 

ringing, not pinging right? Feel the shifter to make sure it's not ping.
Ringing is probably just something loose that vibrates at that higher frequency. In my car all of the change I have sitting in the coin holders vibrates at a certain rpm; it's really annoying.

 

i had a ringing noise when id hit the mid-to high rpms too, only mine was the belts, the alternator belt was in need of replacement, check those, once i replaced them and got them tensioned right the ringing stopped

peace,
justin

 

This might be a different noise but... I hear a sort of ringing from the air pump hose when its not connected to the air box, see if your hoses are good. Just a suggestion.