Thanks for that info I deffinetley won't do that again, I did only turn it very slightly anti-clockwise so hopefully I didn't cause any problems? Funny you mention the cover bolts as they were so tight they had embedded in the cover itself!! I thought they were going o break when I took them out! God knows what they used to tighten them, Impact gun maybe??!!! Going to try and take the plugs out and have a look with a borescope and get the rocker cover off and have a look, problem is I've got a customer who "dosent want to spend a lot" so don. Know if I should even bother now I'm just trying to satisfy my curiousty I think?? Thanks for all the replies again, very helpful and if I get to the bottom of this one I will let you know.