One problem related to other fuel system tank mounting has been reported for the 2004 Volkswagen Passat. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Volkswagen Passat based on all problems reported for the 2004 Passat.
2004 Volkswagen Passat 4motion, the fuel tank rollover/vent valve on the top of the tank has cracked and is leaking gasoline onto the exhaust system. The tank was filled up on 2/22/2015 and started leaking large amounts of fuel from the top of the tank over the exhaust. This continued until the tank reached 3/4 full. If the fuel tank is filled above 3/4 it will leak fuel until it gets to 3/4. If the vehicle is parked with the front downhill, it continues to leak beyond the 3/4 point. This failure was part of a previous vw 2008 NHTSA mandated recall 08v156000, but only required dealer inspection of the rollover/vent valve and not replacement of the fuel tank with a functional part, if it was not leaking when inspected then do nothing. The rollover/vent is integral to the vw Passat awd tank, and the complete fuel tank has to be replaced. Vw claim as the car was inspected in 2008, they are not responsible for the subsequent failure of the rollover/vent valve.