As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED. AT START OF DESCENT OIL VAPOR SMELL LEFT ENGINE WAS REPORTED. MAINTENANCE ACCOMPLISHED CABIN ODOR TROUBLE SHOOTING TASK CARD 26L00021001 AND WAS UNABLE TO DUPLICATE OR DETERMINE THE SOURCE OF THE ODOR. THE AIRCRAFT WAS DETERMINED TO BE OK FOR SERVICE.