Hi guys,advice please.Just noticed a horrible rumble thru the car at 70 mph plus and it feels like its coming up thru my seat!!!!it was quite bad on motorway this morning and worse on way home from work? any ideas?below 70 its fine and theres no vibration thru steering just from what feels back end of car? also how do i cure detting? is it purly running a higher octane fuel? chheers in advance ...jase

IIRC sounds like the prop shaft bearing wear....usually felt at speeds from 50mph and above

get your balance checked all round also..

 

i had a bit off a vibration in the car from the rear, it turend out to just be my balance, happened again and it seemed i had thrown a couple of alloy weights from one rim, so i have had some fookin expensive stuff put on now with a much better bonder to keep em on the rim.

get your wallet out :eek:

could also be rear box mount sagging putting the shaft bearing out a bit, rear box mount is the cheapest first place to check then bearing

great more expense lol

is it likely to cause damage?

depends what is wrong first

any driveshaft problem can be dangerous imagine a high speed rotating shaft starting to oscilate and then whipping through the bottom of the car into your arse...worst case scenario

could also be rear box mount sagging putting the shaft bearing out a bit, rear box mount is the cheapest first place to check then bearing

 

yeah that a good poss too....also IIRC warped discs or sticking calipers could bring on judder as well but not 100% on that...wheel balancing is a good starter

Unbalanced wheels, HICAS arms?

damn dunno where to start now

what about detonation problems? im running 99 ron fuel at the moment and she pulls hard but i get a sort of rattle at about 3500 rpm that clears above that range?maybe i should change plugs? they where done bout a year ago?

Service every 6000 miles or 6 months IIRC.