It could be no more than the disc shield catching the disc (if its still there) or maybe a driveshaft issue......do you get a clonking noise if you turn the car on full steering lock?
John
The vibration could be set up by slight wheel imbalance causing the effect John describes. You need someone to hang on the underneath of you car at 55 mph and listen
Curiously enough I've almost been there....locked in the boot of a Mk2 Escort (P reg) trying to locate a knock
With these lightweight cars, often the tread of the tyre massively outlasts the tyre carcass, the rubber distorts like hell, loses all flexibility and goes out of balance....
You may well have a point there, Peter.
John
You could well be on the money there Malc - there is (or should be) a shroud around the cat that does tend to come loose, and a couple of jubilee clips sorts that.
Of course the cat is central but the rattle can manifest itself anywhere.
Have a good one
John
Peter,john&Malc...many thanks.
Checked out all items....no problems.Intend to have wheel balance checked out to-morrow.Did not think imbalance could cause "rattling" at certain speed.