problems with my truck

I have a mitsubishi Montero 1998 4x2 6 cylinders 3.0 When the truck lasts approximately 30 or 40 minutes turned on without moving with the ignition air begins to throw white smoke for a while and then it is taken away I would like to know the cause of this problem to be able to solve it thanks ...

Hello the normal failures of the Montero are bluish smoke after they are stopped a good time, you give a pair of accelerates in emptiness you will see a cloud of smoke, if so the problem is in the valve gums that are tan and get hard and therefore do not seal allowing the entry of oil to the cylinders, check that first and warn you, what smell gives you the smoke?

Hello thank you for your answer if the smell that the truck releases before starting to throw the smoke is very peculiar it is like a good welding smell is so peculiar that before it starts to throw nothing through the smell I know that it will begin