how do you know when the timing belt is bad?

If the timing belt had snapped, you would have nothing from the engine at all, it would not even start. This sounds more like an electrical issue. Have a mechanic you trust check it out for you.

The Passat engines are interference engines, which means that if the belt breaks, the piston hits the valves which then snaps of the valve stem and takes a ride in the combustion chamber which junks the engine. The timing belt(s) need to be replaced around every 90k miles

yea he is right we had one come into the shop a month ago and the motor was completly trashed we had to get it refurbished and then we rebuilt it with new parts such a pain i hate volkswagen. oh and dont try to do it yourself cause it requires special tools

if its the 2.0 liter you can check the belt, looking at the engine from the front, look to the left near the throttle there is plastic on the side of the valve cover which is actually the back of the timing cover two clips and you can take a look at the belt if you cant do it yourself bring it to someone you trust

If the engine cranks over easier[faster] than before it cut off, then it probably IS the T/belt. The engine IS an "interference" engine, which means if the belt breaks or jumps a few teeth, there is the likelyhood of piston/valve problems, which means the cyl. head must come off. The 1.8T Passat engines will actually bend the valves so bad that the machinist has a heck of a time getting the valves out of the head. Most ALL of the valves I've seen are bent like an opened up S. VW gives a maintenence belt replacement schedule of around 90K-100K, but I've repaired these engines [T/B problems] with as little as 80K miles. Another problem that is related to the belt problems is NOT using 5-40 Syntec[Synthetic oil], because you end up with slug in the oil pan from build-up, and I've also seen the cams actually seize up in the cam journals and shear the key in the camshaft key/gear from lack of lubrication! T/Belts with W/pump and the belt tensioner kits along w/synthetic 5-40 is the ONLY way to go! Les

Belts, they should be observed by the owner occasionally. When the auto goes in for some sort of service hopefully the mechanic should be taking a quick glance and inform you of their condition, yes remind him to do that for you. It is cheap maintenance, otherwise I sure hope the tow truck is close by ? Autos now a days have one belt operating a number of items such as alternator,radiator fan, and other items as well.They dry out when neglected and will not perform their intended function. Do pay attention to your belts. Arnie Arnie

On the piston for the timeing on the block duz it go up or down? I know its up?