Hi, the mechanic who advised you to do that cleaning thing is completely wrong. First, if it smokes when you start the car, it would be one of two types: white or bluish-white. If the smoke is always present when you start the car, whether it's cold or hot, and it's blue, it could be valve stem seals. Check the oil consumption between oil changes. If, when starting the car cold, the smoke is white and it also hesitates a bit when accelerating, it could be a problem with one or more glow plugs, or the hydraulic lifters might be failing when cold because the oil viscosity grade is too high. For example, if the vehicle should use SAE 10W40 and you put in... 20W50. It would be very helpful to know the engine's mileage, whether it consumes oil and how much, whether it smokes when starting (both cold and hot), if it misfires when starting, and if it smokes while driving. When you have an oil consumption problem, there's no product to fix it, especially in a new car. Best regards.