2000 Mitsubishi Montero smoke

Hi, I recently bought a Montero Sport 2000 but, when it sits on traffic with the motor on, after a good half and hour, if accelerate starts to release white smoke, I am not sure if it is the rings around the pistons or something less expensive, the motor does not make any noises or leaks oil or any other fluids, if you could help me I would appreciate it. Thank you.