As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - ACRID SMELL DURING DESCENT. SMELL STILL PRESENT WITH EITHER BLEED OFF. MAINTENANCE RAN AND FOUND OIL ON NR 1 COMPRESSOR BLADES AND INTAKE. FERRIED TO PDX. IN PDX, REPLACED O-RINGS ON NL PROBE. OPERATIONAL CHECKS GOOD AIRCRAFT RETURNED TO SERVICE.