Can anyone tell me the difference between the dohc and the sohc motor? my brother has a 1999 toyota camry and he said that it start smoking where the timimg belt is which has not ever been changed so we believe it broke. When I put in the VIN # it came up that it is a dohc, not a sohc,

 

it stands for Dual Overhead Cam, which is what you'll find in most modern engines. You can google the difference between it and SOHC.