I am currently looking at a 1.8T. Cranks, but won't start.
If the 'timing belt' caught up with it, would it show up in VAGcom?
Owner claims "drove it in the morning to work, but not starting after work", but who knows.

 

If the timing belt snapped then there is most likely bent valves, The car may be done, also if I was you I would stop trying to start it. If it is the timing belt the engine may lock up. Idk what it is could be low battery or a number of things though.

 

Codes only show up when the belt is off a tooth or two when the engine cannot advance or retard timing as much as it wants to, thats when you get a code, but for that code to show up the car has to be driven. You might get an implausible signal or something like that for the cam or crank sensor too, but I dont think itll be thrown when you are just trying to crank. If you want to see if the belt is broken on a 1.8, you can fairly easily get to the top plastic cover, right at the front of the engine.

 

From what I learned, the timing belt typically does not snap; more common is that it jumps teeth.
I was told that this leads to bent valves (new head or heads), marked pistons (new engines).
Since the car in question here is cranking and turning over fine, it is NOT the battery.

 

When the belt jumps, the car IS driven. So any effect the belt is causing should find its way (per thrown and stored code) into VAGcom.

Any actual codes anyone?

Aside from VAGcom, what else can be (easily) done to rule out 'belt damage'? Compression test?

Since not all 'belt damage' results in damaged pistons, a 'camera' (to look at the pistons) is not a guarantee either (and in case of engines that still turn over, there is most likely no or little piston damage).

 

A compression test will tell you if there is any engine damage. And if im right if timing is off because the cams will open at the wrong time.