VW Touran 1.9 TDI - 06

arcon5

I wonder if a solution can be engineered with the aid of some spacers.

Marktheshark

This could be con rod failure, common on that engine, like a tapping with a pop at the end noise as the piston taps the head and gets slammed back down with the detonation cycle.
Tap, pop, tap pop.
Tap pop, BANG, con rod through engine block.

attila_

Mention it to another mechanic but don't mention the camshaft.

Is it a tapping noise or scraping noise?

Could be lots of things including the turbo shaft has a bit of play. Could also be aux belt tensioner etc.