my Cooper D seems to vibrate/resonate more than it should when cruising along at 75-80 on the motorway - cant quite place the source
still on run flats and the front tyres are getting worn...I guess that can't help but any other ideas?
put someone in drivers seat engine running listen around the gearbox to engine part of engine and box get them to work the clutch pedal if can hear noises and vibration changes pitch then chance are its the flywheel is worn out. they tend to last around 70k on the diesels depending how and where driven, ie motorcar will do 150k easy, and around town car driven at low revs as early as 50k . high torque loads play hell with them. i put flywheels in both my cooper d clubmans around the 80k mark,
also worth after a good drive at motoway way speeds to check each wheel see if one is hotter than the rest is so could be down to a brake caliper sticking, or warped brake disc, worth jack car up spin wheels while still hot see what sound wrong,
remove front wheels check the driveshaft for play un and down and rotational for clunks. check road springs and pull the top by the top strut mount for clunks,,while car jacked up spin wheel rest something against the tyre and spin it see if it rubs on and off as such, same with the thread and rim part as might be bent or tyre might be out of shape,, if car has been parked up for a long time the tyres can sag on one spot .
gear box and engine mounts worth checking
bottom pulley on crankshaft has a tortional damper ie rubber bit in it that fail and vibrate big time, also oil pressure worth checking as if mains worn will also cause a vibration in drive line,