K

KirkGrovesRV8

Well Known Member
Hi fellas
Quick question just took the 8 up for a flight and the #4 EGT went cold the rest of the EGTs were normal between 1350-1450 but #4 was down to 850.
Once on the ground it came right back in line with the others, before shut down I did another runup and all looked normal ( mag check was great)
I did just do a oil change maybe a loose EGT wire???
Any ideas?
Thanks
 
No real major diffrence in the CHT it was around 318 when it happened, and it stayed around that until I reduced power for landing.
 
KirkGrovesRV8 said:
No real major diffrence in the CHT it was around 318 when it happened, and it stayed around that until I reduced power for landing.
Click to expand...

That pretty much puts narrows it down.
Probes and the wires can show intermitent failures.
Your going to have to start troubleshooting them.
My technique on the wiring like this is...
Disconnect the probe wires in the cockpit where they terminate.
Take pin, like a sewing pin, thin, poke one in each end of one wire. One at the sensor end, the other at the other end in the cockpit. Your just trying to get the pin to make contact in the wire.
Hook an ohm meter to the pins using alligator clips or something that will keep them there, preferrably a meter that has sound, and start jiggling and moving things around.
Do that for each wire all along the route.
Once you do that, if nothing is found, you can swap probes around and see if the problem moves, trying to determine if its the probe. You dont want to throw money at a probe till your convinced thats the culprit.
 
Sounds almost exactly the same as one of mine. I replaced the EGT sensor (GRT) and all is well.
 
EGT

On most EGT systems an open wire the EGT goes up, a shorted wire they come down. Same thing with the probes. Sounds like a short somewhere.
 
I had the same experience.

It narrowed down to wire short about 6" from the probe. The two leads from the probe were encased in shrink wrap and eventually touched. The readings were erratic, but repeatable when flexing the wire. Reworked the area and no problems since, about 240 hrs. Knock on wood!:D

Good luck,
David
 
KirkGrovesRV8 said:
Hi fellas
Quick question just took the 8 up for a flight and the #4 EGT went cold the rest of the EGTs were normal between 1350-1450 but #4 was down to 850.
Once on the ground it came right back in line with the others, before shut down I did another runup and all looked normal ( mag check was great)
I did just do a oil change maybe a loose EGT wire???
Any ideas?
Thanks
Click to expand...
Do you have any connecters or loops or too snug tie wraps on that wire? If so, suspect that could be root cause. Heat, airflow, vibration could lead to this problem over time with these types of root cause problems.
 
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