EGT CHT readings false on #1 cylinder

[Remy]

Hello All,
Before starting, all EGT are reading OAT, but after starting, #1 cylinder shows red cross on CHT and a false reading on EGT, very lower than the others
Checked connections, ane discrepancy is still here
Any idea?

 

[SkippyDiesel]

Check that the thermocouple/sensor is working correctly - swap EGT and see of the problem moves or stays

 

[RVDan]

the EGT thermocouples can fail like this. I would swap thermocouples and see if the problem follows.

 

[prepperpilot]

I am having same problems on one CHT probe. Temps All over the place. CHT is consistent. Gunna switch out sensor probe soon. I know it's annoying! Don't freak out

 

[WenEng]

Mine was a poor electrical connection where the thermocouple wire connects to EMS wire.

 

[SkippyDiesel]

I have two EGT probes. Since installation they have never been balanced (the same). Checked everything, decided is just the probe. Reading is consistent on every engine run. Disconcerting at the beginning, now just annoying. living with it

 

[swatson999]

I have two EGT probes. Since installation they have never been balanced (the same). Checked everything, decided is just the probe. Reading is consistent on every engine run. Disconcerting at the beginning, now just annoying. living with it

EGT as an absolute value means nothing. Each probe is going to end up in a slightly different position, different distance from the exhaust valve, slightly different angle in the pipe, any one of a dozen things.

What matters is the *behavior* of the EGT values...do they all rise and fall together when leaning? Do they all rise when you do a mag check, etc.

The actual numbers are kinda meaningless.

 

[Remy]

Be aware that sometimes Dynon inverts EGT and CHT probe labels...check wires colors instead
That was the issue....

 

[swatson999]

Be aware that sometimes Dynon inverts EGT and CHT probe labels...check wires colors instead
That was the issue....

What labels? As I recall, there are no labels on the wires themselves.

Or do you mean you hooked up an EGT probe to a CHT extension lead from the EMS, or vice-versa?

 

[Remy]

That is right
EGT and CHT EMS harnesses are labelled

 

[swatson999]

That is right
EGT and CHT EMS harnesses are labelled

I know. So what do you mean "sometimes Dynon EGT and CHT probe labels"?

Are you saying you got a harness with EGT wires labelled as CHT, and/or vice-versa?