Hi Dandy, They hadn't thats why it was running fine and not burning oil.

As far as I could see they hadn't broken or scored the bore, they had cracked.

Phil.

hi phil,
do you mean that they still drove ok with this problem?or before?did the people in question get them fixed,or drive them `as is`.i haven`t done a compression test yet.would the offending piston give a much lower reading?any ideas whether replacement piston rings are available in th uk ...

Hi Hoggman,

I think what your problem may be is the piston ring has gone. What happens is your van has been left idle without use for a long period of time and when it has been started, the piston ring seizes to the wall of the chamber and cracks and this should be what is causing the tapping ...