Obviously when a large piece of metal is held somewhat loosen, its natural that there would be a bit of vibration in it and honestly speaking why a. ny sensible person would start the car, open the bonnet and would stare it? But yes just for the sake of discussion below 1000 rpms, its vibration d. ue to hyper soft foundations is a bit more than 1300 xli engine as per my experience and the answer for why is very much obvious. This thing is nothing at alls when you look at other goodies of this car as personally I am using it and had used 2004 xli for complete 6 good years