As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INABILITY TO ACHIEVE THRUST DURING REPOSITIONING FLIGHT, ON DESCENT AT 37K THE PILOT HEARD RUMBLING NOISE FROM THE RENTAL ENGINE. POWER WAS REDUCED TO STOP THE REPORTED NOISE GOING DOWN TO 30K. PILOT REPORTED AN OVERTEMP AND ELECTED TO SHUTDOWN THE ENGINE. ACFT SAFETY LANDED.