I have had 3 EGT probes fail.  These were the MGL probes, but they are the dirt simple hose clamp and a probe setup that can be found from various engine monitoring suppliers.  Is this common?  I did not expect to to have one failure in 150 hours much less three.  Just wondering if I got a bad run, or if the high temperature environment causes these to fail. 


Views: 84

Reply to This

Replies to This Discussion

Hi John B! Definitely 3 probe failures in 150 hrs is excessive and as you say, even 1 in 150 hrs is abnormal.  I originally had a Grand Rapids Technologies EIS 6000 and I used their installation kit and EGT probes.  I later switched out the EIS 6000 for a MGL Xtreme mini-EFIS and mini-EMS.  I retained the GRT probes and they worked great with the MGL equipment.  I think I've had only one probe failure in 800+ hrs, and replaced the failed probe with another GRT EGT probe.  Don't know if that's either good luck or GRT sells a superior probe, but it works for me!

I also suspect that probe placement could shorten a probe's lifespan - I "think" my probes are about 120 mm from the exhaust ports.  The recommended placement is likely in the engine installation manual or Nick at Arion Aircraft could verify the proper distance.

John N750A

The Gen 4 engine ships with some pulled rivets in the EGT probe locations.  Just drill out the rivet, enlarge the hole and install the probe.  I will check and see what the distance might be.  I might also check on the GRT probe.  I may have just received some poorly made probes. 

The pre-drilled holes are a good improvement (on the earlier Gen engines you have to measure and drill the EGT probe holes) - the distance from the exhaust ports and location on the exhaust headers will be "standardized" by the factory and that should help make EGT's more relevant to compare with Jabiru's recommendations.


Could it be the wires failing and not the probes themselves? If that's a possibility, maybe try securing them differently so the replacements don't vibrate in the same way.

I've had 2 fail in 400 hours.


New from Zenith:

Zenith Planes For Sale 

Classified listing for buying or selling your Zenith building or flying related stuff...

Custom Instrument Panels
for your Zenith

Custom instrument panels are now available directly from Zenith Aircraft Company exclusively for Zenith builders and owners. Pre-cut panel, Dynon and Garmin avionics, and more.

Zenith Homecoming Tee:

Zenair Floats

Flying On Your Own Wings:
A Complete Guide to Understanding Light Airplane Design, by Chris Heintz

Builder & Pilot Supplies:

Aircraft Insurance:


West Coast USA:

Pro Builder Assistance:


Transition training:

Lavion Aero

K&S Aviation Services

Aircraft Spruce & Specialty for all your building and pilot supplies!

How to videos from HomebuiltHELP.com

Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit HomebuiltHelp.com for the latest DVD titles.

© 2024   Created by Zenith.Aero.   Powered by

Badges  |  Report an Issue  |  Terms of Service