EGT Loss during climb out

[RyanB]

Had something unusual occur during climb out this evening.

I took off and was about 500ft AGL when my EGT’s starting dropping off quite rapidly. I was full throttle and mixture full rich (elevation 860’ and OAT was about 80F). No noticeable RPM change so I continued the climb out and as I pulled the mixture back, I could hear a slight audible increase in engine power. It was as though the engine was too rich and wanted to be leaned back, which is unusual at this elevation. As everything seemed to be okay after leaning, I continued my climb to altitude and everything seemed just fine, EGT’s and RPM’s indicated normal. Once back to pattern altitude, I shoved the mixture full rich again, as I typically do for landing, and the EGT’s seemed to fall off again, though not as rapidly and I could hear a slight change in the engine power. Any ideas what might be going on?

Airplane : Archer II - O360

 

[Jim Carpenter]

Density altitude would have been 2200 feet or so, higher than standard, but maybe not enough to make that kind of difference. Any chance the carb heat was left on?

 

[PaulS]

Time to call a mechanic.

 

[Doug Reid]

Check carb heat door for closure as Jim suggested, also check air filter. It is not uncommon to see an increase in power when leaning on a hot humid day.

 

[Pilot Steve]

I don't know what caused your issue but all I can say is from my experience I would not fly it again without a licensed/certificated mechanic inspecting it to determine if there is a bigger issue brewing.