Q: I have a 2006 Volvo s60 2.5T and when accelerating it vibrates violently.

Hi there. It really depends at what speeds you are experiencing the vibration that might point out a few possible sources. If the vibration is apparent upon instant acceleration (at slower speeds and progressively increases as speed does) it is likely caused by worn out wheel bearings. If the vibration occurs at higher speeds (above 50 mph) then it is quite possible that one tire is either poorly balanced or has a slipped radial belt, which can cause a balance problem that is very difficult to fix and determine on a standard wheel balance machine. It is probably a good idea to have a professional mechanic complete a vehicle is vibrating inspection, so they can attempt to replicate the symptoms and determine what course of action is best to resolve the problems.