Fuel System - Thumping Noise From Fuel Tank Area

20 07 01

March 5, 2007

2014293/1





Vehicles Affected

Thumping, knocking or popping noise in fuel tank area

Condition

Customer may report thumping, knocking, popping or similar noise emanating from fuel tank area during or shortly after driving.

Technical Background





Filtration element was too fine in the original in-line filter (part number 4F0 201 801 A) for the leak detection pump. In some cases, the filter becomes obstructed by particulate build-up that impedes tank pressure normalization. This condition leads to nonlinear corrections in tank pressure, thus causing a thumping noise.

Production Solution

Vehicles produced after the specified VIN break are equipped with an improved filter (part number 4F0 201 801 B).

Service








Replace in-line LDP filter with improved part 4F0 201 801 B and verify elimination of the noise.





Warranty





Required Parts and Tools