Now I know a bit about cars (well I like to think so anyway).
But listen to this...
My mates 16V Astra GTE has got this starnge problem.
We all know about the noisy lifters at start up, but what about this...
No noise when cold... tapping like a tappy thing (couldn't think of anything else) when upto temp???
Just one lifter, and they were all changed 20k miles ago.