My Prius 3 engine block shakes violently and knocking metal sounds bad, it seems like the engine block is about to jump out. I shut the engine off, give it to 10 seconds then it starts up normally. This happens rarely once very several months. My Prius is driving fine, idling easily and mileage is very good. YouTube has so many suggestions like blown head gasket, EGR valve, bad spark plugs.. Any Prius owner had this experience and fixed (DIY)? I need to be proactive to take care this issue, my Prius has 160K, thanks.
