Have you just flown through a shower? Older systems with firewire can sometimes get a drop of water that does not drip off and tends to evaporate. Sadly during the evaporation it tends to boil (hot engine) and can give you a spurious caption. Anyway, back to SSE and look for signs, normal guage scan and the odd turns to look over your shoulder for smoke. Positive signs, close it down. No positive signs, GI the the engine, now the dodgy bit!! caption remains, close it down and recover. Captions clears, leave it at GI and monitor, might!! use it for landing, depends on loads of factors, captaincy decision! all sorts of reasons, hot gas leak etc. Works for me