The dipstick only reads the "top" 1-1.5 quarts of oil. If you were 1.5 quarts low, the dipstick would show no oil on it (as you observed). If you then added 2 quarts, you would be overfilled by a half a quart. If you overfill enough, it's possible for some of the engine components to spin in the top of the oil in the pan and froth it, which is not good for the oil system (but an eay fix - let a quart out of the bottom). Anyway, this is apparently what happened to you, so you didn't run the engine dry, which is good. Any VX over 50k miles (which is most of them at this point) needs to be monitored for oil consumption very closely - it's cheap to add a quart when the engine needs it, but very expensive to repalce a seized engine that didn't get its oil. We should call it the "Know before you blow" campaign...

As for your engine problem, that's a whole other ball of wax, and I can't help you much with it from across the country. Good luck, though!