Went to the grocery and on the way back started the car and a loud fast tapping noise came on. First thought was perhaps the fan was touching something. Noise level reduced significantly after about 30 seconds and drive the mile home got it in garage and opened the hood. The noise was/is loud. Almost sounds like a grinder or a skill saw. Checked the oil and it was very low. Topped off oil and started again, let it run for about a minute thinking perhaps it was dry on top. No change in the noise, it is loud. Drivers side. Dont care to start the car again even to get to mechanic. Any thoughts on this?http://members.roadfly.com/me_iam/BMW-003F.jpg

91 850i Calypso
01 740i Sport
94 Yamaha V-Max Mod's 120+ HP