EGT thermocouple failing

[billnaz]

On my last flight #2 egt reading was 100-200F lower than the rest and irratic. This is a new occurrence, and a little disconcerting. Engine sounded fine and no other abnormals noted. I switched #2 and #4 sensors and verified that the reading followed the sensor. So, it's a PITA rerouting job for the new sensor.

My question is, how often do these thermocouples go bad? Should I change all four now? Engine is 314 hrs TTSN. Any insights would be appreciated.

Bill

[ronschreck]

Mine have been going strong for 1330 hours. One is starting to become erratic and I have ordered a replacement.

[airguy]

I lost one on my 172 at 700 hours, no other experience with them.

[rocketbob]

The K-type probes made by KSAvionics have an inconel jacket and will last a long time. A few of the EFIS vendors use their probes. They're nominally more expensive but worth it.