I know, f**k knows why it was so tight as i had it out last year and i remember only pinching it up although it was never in good condition from when i got it from the previous owner so it's my own fault for not replacing it last time. I even tried whacking an Irwin bolt extractor on the remaining stub but all that did was fracture the alloy pan around it - meh!

That aside, I'm starting to think it might be the cam chains - How big a job is it to replace these?