As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL 370 ENGINE ANTI ICE WAS TURNED ON, SHORTLY AFTER MANIFOLD OVER TEMP LIGHT ILLUMINATED MANIFOLD TEMP (RT) REACHED RED ARC. COCKPIT FILLED WITH SMOKE AND FUMES. COMPLIED WITH CHECKLIST AND TURNED NR 3 ENG ANTI-ICE OFF. MANIFOLD TEMP RETURNED TO NORMAL. OVERTEMP LIGHT EXTINGUISHED AND SMOKE WAS EVACUATED. REMOVED AND REPLACED NR 3 ENG PRECOOLER CONTROL VALVE. LEAK CHECK OPS CHECK GOOD.