What cause the clicking sound from underneath left front wheel or engine Toyota Camry LE 1999 when the car start to move and disappear when the car speed increase?

Sounds like a CV axle. (constant velocity axle) its the part on your car that turns the front wheels. it is a bar with joints on each end. the joints are in a rubber boot. this sound is most likely caused by the rubber boot tearing or slipping off and expelling all the oil. now your joints have no lubricant and are probably warped. this happend to my 1993 Toyota corolla 1.8l. to check yourself turn your wheel all the way to the left and park the car. MAKE SURE YOU TURN THE CAR OFF! now lay near the front of the tire and look behind it. there should be the bar i described. look at the rubber boots on each end if they don't appear OR feel to be torn then this is not your problem. if they are get it fixed. this is not a severe problem until the car makes this noise on a strait away but still you may want to get it fixed.

DELUNATIC