HELP! OH, **iT Think its F**ked

I'm getting a metalic knocking noise from the top of the engine. It makes the noise when oyu come off the throttle. I've heared roumors that it could be a 'new engine' job! Any ideas about what it could be, and if the work needs doing could it be done by an enthusiastic home machanic?

All your help is apreaciated!

Oh its a 90 mkiii non turbo

sounds like a valve job to me

bent rod?