EGT intermitent

[ajg6989]

My EGT gauge has started to read nothing every once in awhile

[trbankii]

I'd check connections and grounds.

Alternatively, it is possible that the sensor is failing. What is its age?

[DmaxMaverick]

It may depend on the type of gage you have. If you have a millivolt gage (thermocouple wire connects directly to the gage), it's probably the thermocouple or a poor connection (the gages rarely fail). If you have a gage requiring an amplifier, it could be the thermocouple, wiring, amplifier, or interference.

On mine (Isspro amplifier mounted in overhead console), any radio transmission (Motorola 2-way) will cause the gage to "zero". Other interference will do the same, if the conditions are right. If I hold my cell phone near it, the gage will zero. If you have a cell phone, radio transmitter or other RF generating device (or antenna) near the amplifier, it may do the same.

When selecting a thermocouple, always choose one well above your expected range of use. If you have a 1,500° gage, and use a 1,500° thermocouple, the thermocouple won't be as durable as a 2,000°. They cost a little more in the short haul, but you will have to replace it sooner (typically about 1/2 the time, depending on how much use is near the max). Most post-turbo applications are fine with a 1,500° thermocouple, while pre-turbo should use a 2,000° for similar life expectancy. For reference, long-term sustained use should be less than 50% of the thermocouple's range with only occasional use above 50% for longer life expectancy. In any case, thermocouples do fail at some point, with the life depending on the amount of time used nearer the range max.

[ajg6989]

mid to late 90s when a new 6.5l was put in the suburban