As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED BLOWER VERY NOISY/GROWLS IN OPERATION. CLOSER EXAMINATION REVEALED VERY ROUGH SHAFT BEARING. A NEW REPLACEMENT MOTOR WAS INSTALLED. THIS BLOWER MOTOR IS USUALLY VERY RELIABLE IF A BIT NOISY IN NORMAL OPERATION. LIKELY CAUSE IS POOR QUALITY OR INSUFFICIENT GREASING OF THE BEARINGS BY MFG. (K)