When the wheel is straight hear nothing but when the wheel is turned slightly to the left I hear a knocking sound like something is hitting something? cant find it....any help is appreciated.

-David

 

hmm, might be your wheel bearings. dont quote me on this though.

does it start making that sound when your under acceleration? around 3000rpm -/+ 1000

 

Jack up the wheel in question. Grab the spokes and wiggle. Your steering wheel may turn, but If there is any play between the hub and knuckle, your wheel bearing may be done. If there is no play, I would check the rear hub and axle boots.