well, i didn't take off the lower timing cover to try and turn the crank. Im assuming the worst... the engine does not crank... the serpentine belt does turn, but that's it... the timing belt is tight and appears intact. Here is a video..

 

So it sounds like the starter is not engaging the flywheel and that may be because the starter is going or something is blocking the piston from completing its cycle like a dropped valve. Looks like you will have to get to the crank bolt to see if you can turn the engine by hand. If you can then you will have to diagnose the starter. If you can’t then my suspicion of a dropped valve is most likely true.

I just went through this with an A4 I bought with an engine not running. Same thing happened. Stopped all of the sudden. When I took the head off, this is what I found.





I ended up rebuilding the entire motor and head as a learning project.

If you dropped a valve, you will most likely require a new engine unfortunately as there will be piston damage and head damage like above.

A quick way to see if there is damage is to take the spark plugs out. If there was a valve bouncing around, the spark plug will be hard to take out and look like this. You can also shine a light down the spark plug hole to see if you can see anything but the tell tale sign is if you can’t turn the engine over by hand. Let us know what you find.

Doug