EGT?

[Sling 2 Pilot]

Hi Paul, have got an EGT question for you.
So, Absent a bad probe, I’m seeing my #2 EGT temp occasionally going into the caution zone on my EFIS. It has, ONCE OR TWICE A YEAR AGO GO, gone RED, where upon I reduced power and all was normal, even after increasing power again. It was really cold that day.

On a flight yesterday, it went to yellow departing Brandywine airport, 1570 degrees if I recall correctly. I climbed to FL055 back home just shy of full power with no issues. EGT’s for the flight down were fine, as was the return after that initial spike.

I’ve got an oil change coming up next week and plan on swapping the probe to see if it’s the probe, but absent that, where should I or my mechanic be looking?

By The Way, engine is a 912 ULS, with 170 trouble free hours on it.

[3Dreaming]

You didn't mention which EFIS you have. For Dynon powered airplanes if everything else seems normal my first step is replacing the probe. The Dynon probe is fairly inexpensive, and normally fairly easy to replace.

[RV12Heal]

Whenever I experience or hear of an issue with erratic or unusual sensor indications my first (and cheapest) thought is to check the sensor's wiring -- usually a simple continuity check is adequate for troubleshooting purposes. Clean all of the associated terminal and connections. On some aircraft it is easy to swap sensor leads to see if the issue travels with the leads. EGT sensors operate in a tough environment and as a result have a limited lifespan -- some go to TBO and some seem to fail early. On my RV-12 / 912 ULS / Skyview aircraft I have replaced one EGT probe in 950 hours and it was relatively cheap from Dynon.

[ShawnM]

Agreed, sounds like the EGT sensor, I had the same thing happen to me on a flight one morning. I just replaced both Dynon EGT sensors, no sense in replacing just one, and no issues since then. They do have a short life span and are very cheap and easy to replace. I'd suggest the correct thermocouple connectors rather than use a simple butt connector which is not the proper way to connect K type thermocouple wire.

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IMG_7254 (Small).jpg (42.74 KiB) Viewed 2617 times

IMG_7255 (Small).jpg (43.54 KiB) Viewed 2617 times

[Sling 2 Pilot]

You didn't mention which EFIS you have. For Dynon powered airplanes if everything else seems normal my first step is replacing the probe. The Dynon probe is fairly inexpensive, and normally fairly easy to replace.

Garmin G3X Touch

[3Dreaming]

I would expect the probes for the Garmin to be similarly priced.

[drseti]

Check your grounds. Erratic EGT readings are sometimes the result not of a bad probe, but of a bad ground connection.

[Sling 2 Pilot]

Check your grounds. Erratic EGT readings are sometimes the result not of a bad probe, but of a bad ground connection.

Thanks drseti and others. I’ll have my mechanic take a look at the ground.

[drseti]

I'd suggest the correct thermocouple connectors rather than use a simple butt connector which is not the proper way to connect K type thermocouple wire.

Where did you find those connectors, Shawn? They're slick looking.

[RV12Heal]

Here is one supplier:

https://www.omega.com/en-us/search/?text=SMPW-CC-K-M

[ShawnM]

I'd suggest the correct thermocouple connectors rather than use a simple butt connector which is not the proper way to connect K type thermocouple wire.

Where did you find those connectors, Shawn? They're slick looking.

Thanks Paul, they are actual thermocouple connectors for K type wire. The ones I have are Omega brand like the link that RV12 Heal posted. I bought them on eBay. The connector is made from the same material as the wire. Some dont have holes in the middle but these did so a little safety wire keeps them together. I'm on my 3rd set of Dynon EGT probes and it makes swapping them out a breeze.