Acceleration Noise on 2001 Volkswagen Beetle

Whenever I step on gas for acceleration, I hear
a loud rasping sound from engine area. What could
cause this? Otherwise car runs fine.

Asked by for the 2001 Volkswagen Beetle
Have the same car/problem. The mechanics just changed the water pump and the timer. MIL light came on and the noise. Please let me know if you get an answer.
1 more answer , 1 more comment
Finally took car to dealer. Problem was the catalytic converter causing rattling sound. It was replaced and it corrected the problem. Thank goodness it was covered under warranty.
how did you get this covered under a warranty? i have the same year beetle and my warranty has long since expired.