What was found
NR 2 ENG OVERHEAT LIGHT ILLUMINATED 4 TIMES MOMENTALLY DURING CRUISE. ENG INSTALLED, CHECKED NORMAL. FIRE OVERHEAT AND PNEU SYS CHECKED OK. DESENDED TO FL 220 TO KEEP ENG AT IDLE FOR REMAINDER OF FLT. MASTER CAUTION AND OVERHEAT LIGHT REMAINED OFF. PRIOR TO DESCENT ENG OVERHEAT LIGHT REMAINED ON STEADY, PER POM SHUT DOWN NR 2 ENG AND FIRED BOTH FIRE BOTTLES. REPLACED FIRE DETECTOR PANEL.