GTi engine knocking noise

[slicendice]

My g/f's 65 plate VW Polo GTi (manual, petrol, 58.5k miles) has recently started making a tapping/knocking noise from the engine. It's not a really loud noise but it is noticeable...it makes the engine sound slightly like a diesel. It was serviced/MOT'd about a month ago, so I don't think it's anything related to needing an oil change (though I'd be the first to admit, I have very little knowledge and very few skills when it comes to anything engine-y!).

It doesn't start as soon as the car starts and usually becomes apparent after about 5-10 minutes, so it seems to be only when the engine has warmed up. It only seems to be present when the engine is idling and it disappears when the revs increase. There don't seem to be any other symptoms and performance doesn't appear to have been affected at all - it still drives fine.

I took a video and the noise on there is quite noticeable...can view it here https://streamable.com/deydzv.

The thing I'm slightly concerned about is that it's an indication of something that could end up being serious (and therefore expensive!) if left unresolved. I took it to my local garage (who I use for all servicing and are pretty good) who spent some time checking it out, but whereas they could hear the noise, they said they couldn't find anything wrong and didn't know what was causing it. They said the only thing they could do would be to start stripping the engine down to try and track it down. They also said it could be worth taking it to a VW garage, as it might be a VW-specific issue that they'd come across before.

Either of those options is probably going to start hitting the cash register pretty hard, so I just want to see if there's anyone else who's ever experienced anything like this before, or could maybe suggest a course of action?

Many thanks...

[FlynnByrne]

Hi mate, I’ve got the DSG version same year and my engine also sounds like this after the revs have dropped down after starting, I’m taking mine to the garage next Tuesday so I’ll update then if they find anything