Rattling noise 1.4 TDI

My car has been making a strange scraping/rattling noise for the last 65,000 km, and it's sometimes more or less noticeable. According to the workshop, the timing belt and the water pump need to be replaced.
Today was the day: my car got a new timing belt and a new water pump, among other things.
Result: I didn't have to pay anything... but it's still making a noise! (I don't know what it could be! Does anyone have any idea? The noise is clearly audible when the engine is idling and seems to be coming from the right side of the engine compartment. It's not very loud, but it's definitely noticeable.) As I mentioned, it's slightly abrasive and also a bit uneven.

The tension rollers were reportedly also replaced.