Mike

What is confusing is, it doesn't do it at all. My mate looks after my car and we've had loads of comments from people that its the quietest engine they've heard, it runs fine and there is no slapping that I can hear.

I think the garage where I had my crank sensor done are trying to pull a fast one. I'm driving up North in a few weeks (600 mile round trip) so I'll see what happens with it then.

Thanks for the replies, at least I know what it is now

Matt