(Fri 09:28 03/Jul/09)A worn CV Joint would cause a knocking and a worn wheel bearing would be a rumbling. Also with a wheel bearing the wheel would wobble when jacked up.
mjwman
(Fri 23:11 03/Jul/09)Wheel bearing, not gone but on its way out so no wobble yet.
It is the offside wheel by the way because when you turn left, the off side pressure is relieved.
SpikieMikie
(Sat 18:33 04/Jul/09)It does sound like a wheel bearing. However, turning also puts the suspension under strain and this could cause either rumbling or vibration. In a Civic I owned a worn strut made a popping sound on turning left.
You will know if its related to wheel because the noise will change with the speed of the car.
gary2411
(Sun 08:58 05/Jul/09)check the wheel bearing by putting your foot on thr bottom of the tyre and pulling the wheel towards you