EGT Probes burned through

[jdpainter]

I have 250 hours on my Dynon EFIS D-10A and EMS-D10 in my RV-7A (I really like both units, BTW). One of my EGT probes quit working so I pulled all of them to check them out. They were all burned through.

I always run ROP. The probes are located approximately 2 inches down from where the exhaust exits the cylinder.

How long should these probes be lasting? I know many other folks that have run different EGT probes to 2000 hours+ with no problems.

 

[jdpainter]

Here are some photos of the burned probes:

This was the one that failed completely.  

This is how the other three look.  They all still work, but with less accurate readings that the new probe that I replaced (I had already ordered a replacement probe without checking the failed one first).  

 

[dynonsupport]

2" from the head is pretty close. What temp were you seeing at cruise?

250 hours is pretty short as well, we've heard of them burning up before, but it's generally quite a bit longer than that.

You can use any K-type thermocouple, so if you want to try a different brand, they will work fine with the Dynon system.

 

[jdpainter]

Typically I run ~1450 in cruise...very typical for my engine (XP-360). After measuring again yesterday my probes are actually closer to three inches from the top of the exhaust flange.

 

[dynonsupport]

Yeah, 1450 isn't abnormal. I don't know what caused them all to fail so quickly, but clearly it's systematic to your setup since it wasn't just one that failed.

Are you running Avgas or something else? Really short exhaust pipes? Do small, stainless steel eating rodents call your pipes home when you aren't flying?

 

[DBRV10]

Properly run LOP might be a better idea.... its cooler all round.

Dynon have in their neighbourhood a man called John Deakin, they should and would do well by getting him into the fold so to speak.

He would love to see what you do and you never know, he writes a pretty good article that people listen to especially on LOP ops.

 

[jdpainter]

I think that maybe lots of other customers are having the same problems but don't know it yet. My other three probes seem to be working fine (even though they're reading slightly higher than normal). If the probe on #2 woulnd't have had total failure I would still be clueless about the probe failures as well.

A friend of mine has a -9A with an O-320 and a Dynon EMS w/ Dynon-supplied EGT probes. He pulled his probes yesterday and found the same thing. I would encourage everyone to pull theirs and check them out.

I'm sure I'm not the first one to have this problem. My setup is very stock and I'm running avgas.

 

[uniflying]

Have had a similar issue on the same engine XP-360, the probes don't seem to be very good.

Temps have never left the green arc, so there's certainly no reason why these should be falling apart so easily.

I've also found many others have the same issues with dynon probes across a number of engines.

That said, they are only 50 bucks so we can't exactly expect them to last forever.

 

[kurtfly]

I have used the Electronics International EGT probes with excellent results. Over 1400 hours and no damaged probes on my Glasair w/ Lyc IO360. These are noticeably heaver / thicker than other companies. The only difference you may notice is they are slower to respond.

 

[jakej]

I know this is after the horse has bolted however I never have the EGT probes that close to the cylinder (unless there is absolutely no choice due to slip joints or weldments) as it does reduce the life of them. FWIW  My preference is around 3" from the cylinder.