can anyone explain the difference to me between tappets, buckets and lifters? i posted a thread about a tapping noise on my 2000 172. Having had an oil and filter change, the tapping is still there, so i guess i didnt get away with it!! Anyway the guy who did he filter said it sounds like a sticky bucket (no jokes please) he also talked about changing the shims. Is this worth spending a couple of hours having done before thinking about taking it to a renault specialist and taking out a mortgage?