Common problems with the Volkswagen Passat sedan include accumulation of oil sludge in the engine, problems with the vehicle's ignition system, and excessive brake wear. Sludge accumulation is among the most commonly reported problems and potentially the most severe issue with the Passat, as sludge accumulation can cause the vehicle's engine to seize and fail before the car accumulates 100,000 miles.
The engine sludge problems affecting the Volkswagen Passat are common among vehicles sold from 2000 to 2006, with the 2002 and 2003 model years most affected. Owners who have suffered engine failure due to sludge accumulation report that the vehicle may display a low oil pressure light a few weeks before the engine fails, but engine failure may occur with little warning in some cases. While there is speculation this issue occurs due to the use of oil that is not of the same type as the specific synthetic oil designed for the Passat's engine, some owners who used synthetic oil exclusively have reported engine failures as well.
It is usually expensive to repair an engine that has failed due to sludge accumulation, since the engine must be heavily rebuilt or entirely replaced to resolve the problem. Volkswagen has replaced the engines of some owners who were out of warranty due to the widespread nature of the issue.