TDI Engine Noise: Acceleration Problem?

Hello,
'Recently, I've noticed a kind of 'rattling' sound (resonance noise??? - like something metallic clanging in the exhaust pipe) when I accelerate at full throttle in the lower RPM range (between 1500-1800 RPM). It completely disappears in the higher RPM range (>1800 RPM).'

Does anyone have any solutions or other tips?

Golf IV, manufactured in 2002, engine code AJM, TDI, 115 horsepower, 99,000 km.
Okay, here's the translation:

Thank you.
Razor.

Hi.

What is considered under-revving at 1500-1800 RPM?

That's exactly the speed range where most TDI cars are normally driven.

Please check all the heat shields, especially those located between the exhaust and the body, and in the area of the engine (engine mounts, brake booster).

They can sometimes be loose, but then they can really start to shake and vibrate.

Flex pipe issues are more common in the 1Z engine type.

m,