Just had a look and already been defeated - Two T30 Torx screws to remove the coil pack, and I only have T30 screwdrivers, and no bit adapter for my ratchet handle, so can't get any leverage to get them undone.
Presume if I could get them out, I would be looking for one or more wet/oily plugs that would suggest piston rings?
Going to ring Vauxhall tomorrow (forgot it was Sunday today), and see if they know of any suggest common issues, e.g. replacement cam cover, but is it worth finding out how much a compression test is first and get them to do that as first step?
It's doing my head in - not sure what to do really, and already thinking the worst with regards to big bills. Any suggestions?