As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 3145, THE CREW REPORTED THE ENGINE ONE HP VIBRATION IN AMBER AT THRUST SET DURING CLIMB. THE AIRCRAFT RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE NUMBER ONE ENGINE, OPERATIONALLY TESTED WITH NO DEFECTS, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE. FINAL DETERMINATION OF A SPECIFIC DEFECTIVE PART COULD NOT BE MADE DURING ENGINE MAINTENANCE VISIT EVEN THOUGH HIGH VIBRATION WAS CONFIRMED AT THE SHOP.