EGT spike

preid

Member
Joined
Jan 22, 2010
Messages
754
Location
SoCal
I have noticed that my #2 EGT will occasionally spike up to max red after a couple of hiccups as it moves up quickly. CHT is 320 and steady, than the spike will just go back to normal. Hard to predict. Happened once at run-up, once at cruise. I looked at the pipes and everything looks right, probe looks normal too.
 

jc2da

New Member
Joined
Dec 21, 2009
Messages
279
In my experience, the blade connectors for the thermocouple wires cause this type of flakiness. The hot and cold cycle will work the connectors just ever so slightly loose, then the vibration will finish the job and cause just enough resistance to vary the millivolts and thus temp readings.

As a first measure, i made sure the blade connectors were solidly installed then i put some tight fitting heat shrink over both connectors. The theory is the heat shrink will help hold the connectors together and not let the vibration cycle work them loose.

For the past 50 hours, the heat shrink solution has held up so far. If they go flakey again, i may consider using solder.
 

skydancer

RV-7 O-360 CS Prop. Dual Skyviews/AHRS. TruTrak AP
Joined
Feb 5, 2012
Messages
54
Location
Torrance, California
You are not alone, I have had two EGT failed like that, both were the bad connectors.

The end of the wire bent like a U-shape, the insolator on half of "U" was stripped, the other half was not, so, when factory installer crimps the spade terminal to the wire, only half of the U was contacted with the terminal.

The other half of the insolated wire now pushes against the spade terminal and created a space for the problem to occur.
 
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