Bad rack adjustment can cause that as well as losing a seal on the turbocharger. The turbo starts sucking oil into the engine and the RPMs just keep going up until something goes bang. Had it happen once on a Detroit and we started stuffing what ever clothes, rags, and whatever else we could find down the air intake trying to kill before it killed us. In the old days my dad use to tell the story of the old farmers would be plowing up a hill and start to run out of power so they would carry liquid either with them and when they started losing power they would pour either in the either cups mounted over each cylinder. once in a while they would pour to much in and cause an overrun causing the motor to blow up.

Writing from the gateway to the great BluMtns in southeastern Washington.

Just remember, "You are the trailer park and I am the tornado". Beth Dutton, Yellowstone.