I read a post once that a fella had his cam chain replaced and even still it sounded like a diesel. Saying that the TFSI are noisy engines on tick over.
I went to have a look at at TFSI MK5 once and when on idle if I rev'd the engine, the tappety noise got louder. I left it and walked away instantly.
I've known alot of the Mk5 TFSI engines to sound like diesels on idle, But soon as I rev the engines. the noise should go away. if it doesn't then you have a problem.
If you sit in the cabin and it sounds like a diesel, Rev the engine very slightly. if the diesel noise goes away then your fine.
Hope this clears stuff and puts your mind to ease.