I have a 2004 Passat Diesel and it cost £160 for the replacemnt belt from a VW approved garage.
vw recomend 100.000 but should be done at about 80.000
$0 It does a VR6 has no timing belt. Rick
The 1.8 liter - 4 cylinder and the 2.8 liter - V6 engines have a timing BELT
According to the owners manual, 2005 Passat TDI timing belt needs changing on the 100,000 mile service.
vw's are typically at 60k
Should be replaced every 105,000 miles.
Have a look at this site for a detailed guide to changing the timing belt and other servicing matters. http://www.taligentx.com/passat/
ask a mechanic
This is the timing belt, I think. Takes a lot of expertise. Get the shop manual. If you screw it up, you can damage the engine.