Hello good day everyone, I bought yesterday a 1.4er with 86 hp Built. 2014 from a dealer when I drove home noticed the car vibrating / jerking in the stand, as strong as 3 cylinder car (which was not noticeable during test drive) , then I went back to the dealer and the master said that maybe the spark plug is still not optimal, because the car was standing so long and was not much moved, and recommended me to drive a long distance so that it runs again optimally, if after 2 weeks is still so I can go to the again and look for the error (have yes guarantee) , then yesterday I drove directly 100km and it runs great in the highway, quiet and comfortable, but the vibration is still there in the stand , I really think about it a lot, especially if one of the cylinders is broken what I can not remember, My question, is the statement of the master is logical? And should I wait and drive a lot so that the spark plug is again optimal? What can be the result of the vibration in the stand?