Erratic ship CHT readings

[MoMooneyMoProblems]

On a recent xc I noticed that my ship CHT gauge was bouncing around (in smooth air) from 375-450 while my JPI 700 had them all consistently at 350-360. I know we all primarily just use the EDM when we have one, but any concern from this?

I think of the analog gauge as a backup should the EDM go out mid-flight. Any chance the EDM is faulty and the ship CHT is correct?

[Danb]

Nope, issues with ships gauge no surprise, your set with the JPI

D

[LANCECASPER]

  On 3/27/2024 at 11:09 PM, MoMooneyMoProblems said:

On a recent xc I noticed that my ship CHT gauge was bouncing around (in smooth air) from 375-450 while my JPI 700 had them all consistently at 350-360. I know we all primarily just use the EDM when we have one, but any concern from this?

I think of the analog gauge as a backup should the EDM go out mid-flight. Any chance the EDM is faulty and the ship CHT is correct?

Expand  

Legally, your ship's gauge is the certified gauge even though it's older technology and an old instrument. Your JPI-EDM,  if it's not a 900 or 930 is advisory only.

[Joe Linnebur]

We had this same issue. In the annual, they “cleaned the probe” and now it’s solid. Start easy and work from there maybe?

[carusoam]

Voltages from TCs are incredibly tiny…

1) loose wires

2) broken wires

3) dirty connections

4) oxidized connections

5) worn parts

6) sensor not seated properly in the well

 

It is important to have working from a paperwork perspective…. The ship’s CHT is a required primary instrument… unless you have an alternative certified primary instrument….

PP thoughts only, not a mechanic…

 

Best regards,

-a-