As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - FLT 4218 - DURING FLIGHT CREW REPORTED SMOKE IN COCKPIT. DUE TO REPEAT DISCREPANCY, ENGINEERING DIRECTED MAINTENANCE TO REPLACE THE LEFT ENGINE. MAINTENANCE REMOVED AND REPLACED THE LEFT ENGINE. OPERATIONAL AND LEAK CHECKS WERE GOOD AND AIRCRAFT WAS RETURNED TO SERVICE. (M)