i'm thinking it might be the speed cable but it's weird, it gets more frequent the faster i go, but once the cabin warms up it goes away. any ideas? my guess is the speed cable but who knows

 

It could be - unless it's RPM dependent, then most likely your alternator bearing/s are going bad.

 

i'ts definitely not rev based, and it sounds like it's right behind the dash

 

thats what i was thinkin. if u think it might be speedo cable,then always try the cheapest easy fixes first. maybe lube up the speedo cable.. greasing wont cost u anything . process of elimination. and/or maybe spray wd40 with the little red straw @ the alternator bearings. no the wd40 is not a fix but if the sound goes away for a day or so ,u will no its the bearings ..hope it helps

 

It's the speedo cable, but to be sure you can disconnect it from the tranny and go for a drive and see if the noise goes away.
Last time this happened to me, lubing the cable didn't work. So I bought a new one for about $30.

 

Tighten your alternator cable.
Happened to me already