Hi All,

Three of my EGT probes died (X's all the time), so I installed some new EGT probes on my 914 and they read fine below 300-ish F, but above that, and they all X-out.

The new probes were carefully spliced in (which is OK to do as long as you keep the two leads the same length), so I don't think there's an open in the lines.

I looked in the G3X install manual and I don't see a specific calibration procedure for EGT probes.  Did I miss something?

These are the new probes: https://www.aircraftspruce.com/catalog/inpages/westegt12.php

Any thoughts?


  • Re: New EGT Probes on 914

    by » 10 months ago

    The probes from spruce did not last. These people have some that outlasted spruce ones.

    westach.com they actual make them he said

  • Re: New EGT Probes on 914

    by » 10 months ago

    They are Westach probes, so I'm not sure what you're saying.

  • Re: New EGT Probes on 914

    by » 10 months ago

    They make better probes. I have been fighting the probe failure  issue for 2 years. .  I have tried spruce probes, amazon probes, dynon probes. none seem to last. This problem is on 2 different engines and  i have spent hundreds or thousands of dollars on them . Not to mention 100s of hours troubleshooting , removing and installing . Personally I think there are defective probes in the market probably from China. I mixed the westach probe in with the spruce and remos aircraft parts probe. within 1 year or so less 100 hours they have all failed except the westach.

    I replace the probe and the red X goes away. Just my experience is all I have no knowledge of the garmin unit . It could be wiring, grounding or even if they get bent they can fail. All at one time is odd.

    I was thinking the probes went bad?

  • Re: New EGT Probes on 914

    by » 10 months ago


    How did you splice the thermocouple wire to the existing lead wire?  Solder is not typically a reliable connection to thermocouple wire. The connections at the extension splice must be symmetrical in resistance.  If you use crimp type butt splices and the conductors overlap in one connection but not in the other this can create issues.  Using ring terminals on both the extension leads and the thermocouple leads, then connecting them together with a small screw and nut typically assures the same resistance connection on each lead, and allows for disassembly and removal in the future.  Often these connections are slightly staggered to avoid contact with each other, then insulated.  

    With your Garmin system, the EGTs connect to a Garmin engine interface module where information is gathered and transmitted to the G3X via the Garmin CAN buss.  The engine information module is likely the Garmin GEA-24 and it’s also possible your problem could be in that module, especially if the probes you just replaced are acting like the previous ones. This is not at all likely so check all wiring again before going there. 

    There is no specific calibration of the EGT probes in the G3X, however you can enter “configuration mode” and look at the configuration of that input.  You can choose type K or type J thermocouple, and set up the green/yellow/red zones of your gauge but that information should not need to be changed. You should make sure the new probes are the same type as the previous ones (type J or type K). 

  • Re: New EGT Probes on 914

    by » 10 months ago

    Hi Jeff,

    I did Lineman splices with no solder at all.  I kept the wire lengths the same (there's a warning in the Garmin docs about the wire lengths needing to be the same).

    Sure seems like a solid connection method, but who knows?  Maybe I can try your recommendation of ring terminals.

    "K-Type" is how they're configured in the G3X.

    I've connected both Garmin and Westach and not getting anywhere, so this is really bumming me out.  I really would like to have EGTs displayed.  Maybe I need to try a different sensor...


You do not have permissions to reply to this topic.