2002 Mitsubishi Montero

Engine Mechanical problem
2002 Mitsubishi Montero 6 cyl Four Wheel Drive Automatic 141000 miles

My 2002 Mitsubishi Montero Sport XLS burns a quart of oil about every 500-700 miles. The exhaust pipe is perfectly clean, there is no blue smoke, there is no leaking anywhere, there is no smoke when I crank it. There may be a short puff of white smoke after I first crank it and then give it gas. What might be the problem?
November 11, 2008.

Actualy I had the same problem with my pajero at the same milage and I tried to change the valve stem oil seal. It was good for a shor period not more than 6000 KM. Then it started to blow smoke again after idle for about 4 min or more. I was keen to bye the original oil seals which was in 2 colors( black for inlet and green for outlet) that was according to the spare part number.
Now I'm amazed. What must I do more to stop this smoke puffs?

Sep 22, 2012.