Hi, I assume it is a manual in which case check the clutch switch. This is designed to smooth the revs out when changing gear. The facelift model has it under the clutch master cylinder, pre facelift is somewhere on o/s wing.
HTH,
Griff
I havent but plenty of others have used them ok - especially as you're only after the case. Make sure it's for the D2 and not Rover 75 although I believe this is only important if you're after the innards.
Griff
Is it a silicon hose? I've read that they are not a grippy as the standard rubber hoses. Could it be a blocked intercooler. I'm sure the knowlegable will be along soon.
Griff