Really Low EGT Readings

EGT temp readings vary based on the distance from the exhaust port. Temperature drops about 100 deg F for every inch from the exhaust port. They will last longer at the lower temps. I think you have nothing to worry about.

There is no way that EGT's went from 1370F to 450F. Gas will at 495F and that's at standard atmospheric conditions which aren't present inside your cylinder so you'd need to increase that temp for continued combustion. Gasoline can burn at temps around 1500F depending on some other factors. I doubt all your probes went bad at the exact time and at the exact same temp. Check for an issue beyond the probes.

What is considered a low EGT? I'm running at 5000 rpm, 16L/h, at 4500ft, 75ºF outside, and my EGT reads only 1200ºF/1240ºF, while the other temperatures like CHT 190ºF/195ºF Oil 202ºF seem normal. I'm concerned that 1200/1240ºF might be too low for the EGT readings. The EGT sensor is positioned correctly at 70mm.

Should my carburetor's needle be in the richest position, maybe? (My guess is 4)

William, I am occasionally checking a plane where the nuts holding the EGT probes in place don’t really do their job anymore. In fact all looks and feels pretty tight at first glance but vibrations from the running engine make the probes move backward (in fact moving them out of the manifold a bit). When that happens the probes don’t stick in the hot stream deep enough to produce correct readings. Perhaps you like to check that out.

If it’s not that you most likely need to double check the wiring.

I am with Roger, probes can die one day but not two ore more on the same day/hour/minute…

Hi Peter. Recently I replaced one of the two EGT sensors, my guess at least one is fine. However, I'll double check it.

Regarding the wiring, it could affect both at same time? The EMS is Dynon and I'll confirm the sensor but should be original.

Is there an appropriate way to do a test and compare EGT readings?