4

In a 2004 VW R32, after shutting down the engine, a repeated thump is heard approximately 2 times a second from the rear of the car.

What are the likely sources of this noise? My first thought is something related to the evaporative emissions (EVAP) system.

  • My cars both have a buzzing sound from the charcoal canister (sounds like a little electric motor running, but is just escaping air), so it's possible. – Brian Knoblauch Nov 1 '12 at 20:11
  • Did you check the trunk for stowaways? – Tim Nov 2 '12 at 14:51
  • I have a similar issue with a 2008 GTI. I was thinking fuel/emissions related. It sounds like a motor/pump of some sort? Mine does this while driving sometimes (and it's not the fuel pump, AFAICT). – Nick Nov 5 '12 at 2:18
2

It is most likely a leaking EVAP hose or a leak in the fuel line. Make sure it's nothing obvious like a hose hanging off or a gas cap missing. Also check for a check engine light and have the OBD code read if there is one.

There is also a small chance that your fuel pump relay or fuel pump is the cause.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.