Audi A4 1997–2004 — technical service bulletin
Bulletin 0420 · NHTSA communication 10009876 · issued Aug 26, 2004
Technical service bulletin
communication type
Engine and Engine Cooling
component
1997–2004
model years
8
vehicle entries
Official summary
Oil sludge - warranty extension. Service circular - warranty. *tt
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.