Guys, I need some input.Last week I tracked the car at the Ring in Germany and ever since that time there would be a noise like something is heavily shaking only when I shutdown or startup the engine. It happens not every time but maybe 30% of the time and the noise is only for a second or two (after startup and "the noise" the engine idles normally. I'm seriously worried because during one lap I misshifted (I know, I know...) and the revs were very high for an instance (clutch was not fully released yet). The car idles fine and also seems to go thru the revs normally ; vtec is also still fine.There doesn't seem to be any powerloss as far as my buttdyno can tell. I already checked the engine mounts and they looked OK.

Would there be any damage to my engine? Would a bend valve or something cause these symptoms?
cheers.