does it sound like its grinding like a motor constantly goign for a few seconds and also happens sometime when you hit eject?
if so the sled rails need grease beleive it or not margerine will do so raid that fridge.
while your at it decrease the white cog by 2 clicks anti clockwise at the back of the drive this shoulf fix your problems a bit of lighter fluid on the lense itself with an earbud wouldnt go amiss either make sure its dry and the lanse looks clean and free from gtrime and dust.
"Light travels faster than sound. This is why some people appear bright until you hear them speak"