High EGT

Before I commit more funds, I will try swapping the leads (leaving the probes as is). The Dynon thermocouple plugs (spade connectors ) into a lead from the instrument panel, that terminates on the engine side of the firewall. Will be interesting to see if readings follow the lead or stay with the probes.

Depending on above results, I will replace the supposedly good probe in the next few days and let you know the outcome.

When it comes to computer (Dynon) stuff I am not "the sharpest tool in the shed" - completely forgot that a download can be taken of recent  engine/aircraft performance.

Download now done.

Dynon clearly shows:

# Left EGT always slightly higher than Right - probe & lead swap did not change this.

# "Spikes" in EGT reading consistently appear shortly after engine speed reduction and reduced MAP (lower pressure/higher vacuum).

# Often coincides with change of propeller pitch from Cruise to Climb - coincidence ?

# Left EGT seems to have a slightly greater response (alarm sounds) to above BUT this might be because its reading higher, from engine start       onwards.

This seems to suggest there may be a small air leak in the in the carburettor induction system - low RPM/ reduced MAP pulling more air in - causing a brief lean mixture/high temperature situaton.

Hope to investigate today.

Dynon told me their EGT probe should be good for at least 200 hrs. After that it’s anyones best guess I’ve replaced a number of them. Some around 300-400 hrs. and others make it to TBO without issues. Just the luck of the draw. They are easy to replace and I keep 3-4 on hand all the time.

Thanks for that Roger,

If you look back you will see that I have replaced what I thought was a defective EGT probe - no change.

Do you have any comment, on my last posting, referring to the Dynon record of engine performance???😈

Hi Sean,

if the bad reading only affects one probe and you replaced it I’d speculate it is a wire after the probe. p.s.

So long as that cylinder is running okay. It can only be so many things.