when the timing chain lets go, good by engine.
I had one break cruising at 65 mph, "What`s that noise"

. by then it is too late. there are quite a few revolutions on the engine from the time you hear it and you finally get stopped. had oil and coolant and wasn`t running hot, so after checking under the hood, decide to try to start it, Bang Bang Bang. Hmmm not good
I pulled the head, and a valve hit every piston, broke off first cam tower at the base, second one just under the cam, cracked the head, and the last rocker was twister around like a pretzle. but didn`t snap the cam shaft. Oh, and the valve cover had a crack down the side.
These engines are an interference engine when things go wrong.
hopefully this SD is an easy fix.
Charlie