Sons 300m and I need help please!

So.
Got it running kinda. Was idling rough and then just stopped. Not sure how to explain it. It didn't shut off and putter to a stop, it just stopped. Like it was mechanically stopped.
I pulled the front of the motor off again and checked the timing belt / marks. All was good.
We started it again and there is a knocking coming from the top of the motor. Sounds like a rod but from the top end, not the bottom end.
I plan to remove the intake / valve covers this weekend and take a look.
In the mean time, looking for a new car for the kid. He is wrecked..