strange values CHT

[jekroth]

I have a factory-built MCR with Rotax 914 and Dynon D180. The plane is 12 years old and has 500 hours and now I have got a strange error.
When I use a larger electricity consumer type flap, CHT and oil temp go up. It differs on what temperature the engine has, if the engine is cold everything works normally, if CHT and oil keeps 88-92 degrees C. then the value of CHT increases 2-4 degrees if the engine is warmer 100 100+ then the value of CHT and oil increases with 20-40 degrees +, When the electricity consumer then stops, the values return to the original. Recently, the same error has also occurred when using the Autopilot (it is standalone not Dynon)
has anyone experienced anything like this?
I am looking for earth points and for oxide in connection No change in the electrical system has been made.

 

[airguy]

You are seeing a difference in voltage between your engine instruments and the rest of the airplane - this is quite likely a poor engine-to-frame ground that is seeing more load from the alternator when the electrical load increases, when you are moving flaps etc.

 

[Raymo]

Ensure you have a good, clean ground between the engine, battery and EMS box. A dedicated ground from the EMS to engine is recommended, along with a large gauge ground from engine to airframe/battery.