EGT & CHT probe failures

chrish

New Member
Joined
Oct 26, 2021
Messages
4
Has anyone else experienced excessive EGT/CHT probe failures? We have had our HDX system for just under a year (135 hours) and I’ve already had to replace 2 EGT and CHT probes, then this morning one of the new EGT probes is failing again. They are easy enough to replace, but the failure rate seems excessive. I’m wondering if there is something else I should be looking at.

Failure mode is that the reading jumps all over the place and eventually X’s out, generally within the next flight or two.
I had a sensor fail after 6 hrs. on my new homebuilt with a Jabiru 3300 and Dynon D180. It was not connectors or connections. The probe read open circuit with an ohm meter. The connection in the probe was broken. The probe looked fine except for a bit of normal dirt and discoloration. From reading these posts it seems it is far too common. At $53.00 Cdn +freight. This is not acceptable. I now have about 35 hours with no further problems so far. Hope it continues.
 

fastfred58

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Joined
Aug 6, 2020
Messages
24
Has anyone else experienced excessive EGT/CHT probe failures? We have had our HDX system for just under a year (135 hours) and I’ve already had to replace 2 EGT and CHT probes, then this morning one of the new EGT probes is failing again. They are easy enough to replace, but the failure rate seems excessive. I’m wondering if there is something else I should be looking at.

Failure mode is that the reading jumps all over the place and eventually X’s out, generally within the next flight or two.
I have had the same problem. When i told them about it they said there was no issue with them?
 

fastfred58

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Aug 6, 2020
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24
I have had the same problem. When i told them about it they said there was no issue with them?
I realize they are not that expensive but the trouble shooting and replacement is ,not to mention canceling flights when the warning shows up
 

Spert

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Joined
Dec 26, 2020
Messages
41
I have had the same problem. When i told them about it they said there was no issue with them?
Based on my very limited experience, it would appear they are correct. The probe turned out to be fine in my case once I went to a better connection. I have 6 hours on it since the fix and it’s been solid the whole time.
 

Cesar

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Joined
Nov 20, 2019
Messages
11
Location
Chile
Has anyone else experienced excessive EGT/CHT probe failures? We have had our HDX system for just under a year (135 hours) and I’ve already had to replace 2 EGT and CHT probes, then this morning one of the new EGT probes is failing again. They are easy enough to replace, but the failure rate seems excessive. I’m wondering if there is something else I should be looking at.

Failure mode is that the reading jumps all over the place and eventually X’s out, generally within the next flight or two.
in our ecently installed HDX screens we had two probe failures,we changed the connectors and in a year and a half we have had no problem
 

Cesar

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Nov 20, 2019
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11
Location
Chile
Even following the instructions in the manual I have not been able to make an approach using VNAV,does anyone heve experience in this ?
 

Spert

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Joined
Dec 26, 2020
Messages
41
Even following the instructions in the manual I have not been able to make an approach using VNAV,does anyone heve experience in this ?
Is this an autopilot question, or are you not seeing the glide slope information?
 

GalinHdz

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Mar 3, 2008
Messages
676
Location
KSGJ/TJBQ
This is what Spert is talking about.
GS.jpg
 

vlittle

Active Member
Joined
May 7, 2006
Messages
501
FYI - the ONLY ones I use are as mentioned in post #14.

IF anyone still has the single conductor wire (ie 1 strand of wire) in the harness or the probe then you most probably will have ‘issues’ with temperature readings.
the post above is my trade secret #1 ;) # 2 re the single strand of wire - is to strip 5/8” of insulation off & fold the wire 2 times, & squeeze them together, so that in effect you’ll have 3 strands inside the terminal to better ‘fill’ it & then crimp it. There is no reasonably priced tool to crimp a single (very thin) wire conductor as mentioned above. YMMV of course;).
I will make an important statement here: In my opinion, Jake is one if the most experienced Dynon users on the planet. You can pretty well take what he says at face value. In my case, I replace all of my TC connections with butt-splices from AMP (PIDG type). When the probes wear out, I just cut them off and crimp on a new splice. I have plenty of service loop in the wires for this. This eliminates any mechanical connections. Vern
 

rjones560

Member
Joined
Dec 13, 2019
Messages
44
Location
Las Vegas
Has anyone else experienced excessive EGT/CHT probe failures? We have had our HDX system for just under a year (135 hours) and I’ve already had to replace 2 EGT and CHT probes, then this morning one of the new EGT probes is failing again. They are easy enough to replace, but the failure rate seems excessive. I’m wondering if there is something else I should be looking at.

Failure mode is that the reading jumps all over the place and eventually X’s out, generally within the next flight or two.
They don’t last forever, but one thing that can diminish their life is drilling a hole that is too small in the exhaust pipe. As the tube heats up the hole gets smaller pinching the probe. Make sure the holes are the size Dynon specified.
 

Spert

Member
Joined
Dec 26, 2020
Messages
41
the glide slope works perfectly on all airfields but it doesn't work for me and it doesn't appear when i want to do a vnav descent, my screen is a Dynon HDX 100 and the approach data is in the airmate software
It sounds to me like your talking about autopilot use vice approaches. Can you clarify?

If it’s working on approaches, but not when you are doing an enroute descent, you may need help from someone who has the autopilot, which, unfortunately, is not yet available for my PA-32
 

Spert

Member
Joined
Dec 26, 2020
Messages
41
Cesar & Spert - please start another thread. Cesar’s OP has morphed from EGT to GS etco_O. changing threads like that makes it hard for others using the search function to get all the information possible.;)
Can one of the admins help me separate the GS discussion and move it to another thread? Posts 28-32 and 35-38 should all move to VNAV/Glide-slope indications.
 
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