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High EGT Warnings

f1rocket

f1rocket

Well Known Member
One of my EGT signals gives me a warning every time I fly. Why should I care? All the other engine numbers are fine, and all the plugs are a nice Gray color. It runs great and I'm not inclined to worry about it. Should I?

I suspect a probe issue is causing it but even if the probe checks out fine, why would this be an issue?
 
I just had this issue with D-180 EMS. Replaced thermocouple and problem is fixed.

Dynon EGT, Hose Clamp, 0.75-1.25", Rotax
SKU: #100405-001 $47.00 shipped.
 
f1rocket said:
One of my EGT signals gives me a warning every time I fly. Why should I care? All the other engine numbers are fine, and all the plugs are a nice Gray color. It runs great and I'm not inclined to worry about it. Should I?

I suspect a probe issue is causing it but even if the probe checks out fine, why would this be an issue?
Click to expand...

I had the right one go...ordered a couple of extra...replaced the right...working fine....guess what?

...the left one is acting funky.

I think there might be a bad batch out there imho.

Yeah..... you can fool with recrimping/new connectors - that might be it....:rolleyes:
 
Could you mention how many hours you got on your probes?
My right EGT probe acted funny after my annual with wild fluctuations ending with the red cross (no, not this one, the one on the Skyview:D). That was at 140 hour. It bothered me a while and I ordered a new unit but before installing it, I noticed that the wire going to the probe was very tight so I gave it some slack: problem solved. Twenty hours later it still works fine... and I have got a spare!
 
WingedFrog said:
Could you mention how many hours you got on your probes?
Click to expand...

As per post #3 above... I replaced my right EGT. It started acting up ~ 80 hours. It sort of healed itself for the next 15 hours and just two weeks ago it decided to give me grief. I tried re-crimping the connectors and fooled myself into thinking I had it fixed. New thermocouple purchased directly from Dynon fixed the problem and easy install with removing top cowl only.
 
You can always swap it with another probe (like 1&3 or 2&4) and see if the reading follows the probe or cylinder. Don't need to swap the connections. The probes do fail, mostly open up or wiring failure. If you've installed all the probes the same distance down the pipes from the flanges the EGT's should all be pretty close if the mixtures are closely equal in all the cylinders.
 
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Thank you for all the replies. I have 202 hours on the airplane as of today. The probe has been acting this way for some time so I'm not sure when, in terms of hours, it started happening. I used to get a big red X on one of the probes until I redid the connections, tightened them up, and wrapped them in silicon tape. My limits are set at the original Van's set-up limit, which I think is 1480 F or there about.

I'm pretty sure the probe is probably going bad so it wasn't so much of a question of "what to do" but more of a "what's the big deal". I don't know what value the EGT is on a Rotax since there's no leaning. I guess it would be a quick indicator of a fuel/carb problem on one side of the engine.

I may bump the limit to eliminate the warning until the probe fails completely. I'll replace it then.
 
FWIW,

I recently had a similar problem on my Jabiru engine with GRT instrumentation. Discovered an open ground on the #2 probe. This open ground was affecting all of my EGT indications.

Ordered a new probe set from GRT and problem solved. They sold two types of probes, one type was a more durable longer lasting probe. They said the less durable set typically failed around 150 to 200 hours. My probe failed at 145 hours.

Don't know if Rotax uses the same probe manufacturer. I think I paid $13/probe more for the higher quality set.
 
My right EGT indicates about 80F higher than the left EGT at cruise power setting. I?m curious if others experience anything similar. Perhaps right carb/cylinders are making slightly more power than left side? Engine/prop run extremely smooth...
 
Piper J3 said:
My right EGT indicates about 80F higher than the left EGT at cruise power setting. I?m curious if others experience anything similar. Perhaps right carb/cylinders are making slightly more power than left side? Engine/prop run extremely smooth...
Click to expand...

This is exactly what mine is doing.
 
That is exactly what mine did, I removed all the connectors, did a recrimp of all new connectors and it still read high..then started going wonky every once and while....

Put a new one in and it reads fine.

Probes, floats and regulators boys...probes and floats and regulators.
 
cactuspilot said:
That is exactly what mine did, I removed all the connectors, did a recrimp of all new connectors and it still read high..then started going wonky every once and while....

Put a new one in and it reads fine.

Probes, floats and regulators boys...probes and floats and regulators.
Click to expand...
To clarify... You installed a new EGT and it fixed wonky (your term) readings and also right side reads ~80F higher than left side?
 
Piper J3 said:
To clarify... You installed a new EGT and it fixed wonky (your term) readings and also right side reads ~80F higher than left side?
Click to expand...

Yes, my EGTR has always read a little higher during it's non-wonky stage. I think it is the proximity to the oil tank...I have tried a little fire/heat wrap around the end of the probe when it gets close to the tank to no avail.

Pre-Fail and high and sometimes wonky:

vqk2s9.png


New Probe still reads a little higher:

2cdws4h.png
 
Thanks for the confirmation. Proximity of oil tank could explain differential in EGT's.

Love VAF... :D
 
Do not allow any header wrap on the EGT probe.Do not over wrap or under wrap the probe. The header cloth should be at least 1/8" + away from the probe. Neither Dynon nor Rotyax know the exact cause of the interrupted EGT signal. It works on millivolts so it doesn't take much. It has demonstrated that the cloth and the probe are not compatible and can cause EGT temps to flux as much as 125F and usually to the high side. The oil tank will not effect the EGT probe. The probe is inside the exhaust pipe at temps around 1300F-1500F. The oil temp of 215F won't have any effect and the probe would have to be in the oil itself.

An EGT spread of 80F can be very normal for some engines. It depends on several factors. Carb sync, probe placement, internal carb wear, air filter, ect...
An EGT temp with only a 15F spread is considered the same. EGT temps differ with throttle settings and will move up and down and closer or farther apart depending on the throttle settings.


Bottom line don't worry about an 80F spread unless you know you did something that effected the burn and can correct it.
 
Sink said:
Do not allow any header wrap on the EGT probe.Do not over wrap or under wrap the probe. The header cloth should be at least 1/8" + away from the probe. Neither Dynon nor Rotyax know the exact cause of the interrupted EGT signal. It works on millivolts so it doesn't take much. It has demonstrated that the cloth and the probe are not compatible and can cause EGT temps to flux as much as 125F and usually to the high side. The oil tank will not effect the EGT probe. The probe is inside the exhaust pipe at temps around 1300F-1500F. The oil temp of 215F won't have any effect and the probe would have to be in the oil itself.

An EGT spread of 80F can be very normal for some engines. It depends on several factors. Carb sync, probe placement, internal carb wear, air filter, ect...
An EGT temp with only a 15F spread is considered the same. EGT temps differ with throttle settings and will move up and down and closer or farther apart depending on the throttle settings.


Bottom line don't worry about an 80F spread unless you know you did something that effected the burn and can correct it.
Click to expand...

I didn't wrap the probe itself or the exhaust pipes....just a portion of the spring and wire coming out of the probe in close proximity to the tank and it was only a few inches. Wrapping pipes is generally not a good idea so I have heard.

My carbs are super synced, my air filters super cleaned, my floats are new (er).

As for the tank not causing the higher EGTR...do all 912 installations on other LSAs run ~80 degrees hotter on that R side?
 
EGT difference

After I sync'ed my carbs, my right EGT now runs about 50 degrees warmer at cruise. Engine has never run smoother and it has remained very consistent over the last 30 hours. After all the other comments on this thread (and talking with the guru's at Lockwood) I am not worried about this difference.

On another note- I also had a bad EGT probe(left side) around 150 hrs- put in a new Dynon probe and no further problems (i.e. high EGTs).
 
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