EDM 830. Easy from the paperwork and a fantastic instrument. Make sure to get the carburetor temperature probe as well, that could save your life in a O-470 C182.
Achim
I was thinking of something a bit more basic (also that would fit in a 2 1/4" hole) to replace the current single EGT
The original EDM700 is a 2.25" instrument. EI make a similar thing, and they claim some better features and better (thicker wall, longer life) EGT probes.
These instruments are relatively cheap (especially if bought from say Aircraft Spruce) but the labour can be significant, due to the amount of wiring.
loom should not be a problem i can get some guys at work on the case do u know anything about paperwork stress for EDM700 or EI?
for a G reg 182?
Hello,
I had an unstable value on cyl#3, which made the Lean Assist process impossible at the beginning of the flight (second flight of the day).
A few minutes later, the temp was fluctuating a lot, being at 0 for long periods.
(sorry for the bad definition)
Everything else was smooth and fine, and others parameters all as usual.
Would you confirm a failed probe ?
Have two probes swapped, this way you can rule out bad connections, although a worn probe is quite likely.
I changed 4 of them in one year (although some of those were a couple of years old and now reached their life limit). But I also had a new one fail after a couple of months. € 120 per probe and one hour of work.
If everything else is stable and the engine is running fine it’s the probe for sure.
EGT probes get eaten by the hot gases every few years, I have found.
The clue is that initially the reading goes up (not cleanly though). This is because as the probe gets eaten away, the instrument’s “open thermocouple protection” circuit (basically a pullup resistor) makes it look like the probe is outputting a higher voltage i.e. indicating a higher temperature. After a bit the reading becomes physically impossible for a petrol engine (say +2000F) and finally the instrument decides it’s a duff probe. Together with a good CHT value and the engine running otherwise fine, the situation is confirmed.
EI make probes which should be compatible with the JPI instrument (they are all J or K thermocouples; just get the right one) and which are claimed to last longer because they are thicker.
Swapping first ok.
I was a bit surprised during the flight.
But I think I had seen your video Peter, so I had an idea about what it could be, and felt comfortable.
EuroGa is a good place to learn about “semiotics” through “clinical cases” 
