As I start the engine of my vehicle, an annoying noise becomes audible but after driving for some minutes it sometimes stops, and others it can even be softly heard all the time. This noise has become more and more frequent and it seems as though one of the cogwheels is displaced.
Broken studs cause hot air leaks and subsequent gasket damages. As it is a metal gasket it vibratres and that is the noise you hear when starting the vehicle. You should then change the studs to some more resistent ones and your problem will be solved.