R.T.D.H.S.P.

I have a 2002 CTD. My problem is as follows: In park or at low idle in drive I have an extremely loud grinding type noise coming from what sounds to be the top portion of the motor. Under acceleration, however the noise disappears. When I let off the gas, the bad loud grind comes back. When I kill the motor, the bad grind persists until the crank completely stops rotating. The only code I have is the P0216 (injection pump timing failure). Will a pump on its way out make such a noise? Could it be my harmonic balancer? A valve? HELP!!!!!!