citroen c5 2.0 sx vibrates

[bendeguzszabo]

i have a so far unsolvable problem with a Citroen C5 2001 2.0 sx (petrol)

the cars body always starts to vibrate at high speed(highway), as well as the steeringwheel.

at low speed(in town) the vibration happens randomly, usually when parking (especially when i have to make some adjusting) or at red traffic light while the engine is idle, or after shifting, etc. so something goes wrong and the car starts to shake as an alcoholic for some time and after a while all the symptons go away and it works like before.

when the vibration occurs the car is really
- loud like a diesel truck,
- the engine lacks of power and has
- high fuel consumption (12l +)

as not being an expert iam not sure what other information is needed to identify the problem of this car. iam happy to write down any needed details if someone is willing to help me out. i would be greatly thankful.

thanks,
b.sz.

[GiveMeABreak]

Gearbox / driveshafts possibly, but ideally you need a diagnostic done ont he engine management system as a minimum.