Stuck exhaust valve?

[flyingcheesehead]

The plane's in the shop again. Left engine #5 exhaust valve stuck open on the way home.....

Bruce,

Just curious... What symptoms did you see? Did you make it home? Was the valve all the way open, or just not closing all the way? Was it obvious that there was a problem and what the problem was?

My guesses for symptoms... Some power loss, possibly backfiring due to unburned fuel being pushed out the exhaust valve during the compression stroke, and very high EGT due to burning gas exiting the valve during the power stroke.

Thanks in advance for the education.

 

[bbchien]

Bruce,

Just curious... What symptoms did you see? Did you make it home? Was the valve all the way open, or just not closing all the way? Was it obvious that there was a problem and what the problem was?

My guesses for symptoms... Some power loss, possibly backfiring due to unburned fuel being pushed out the exhaust valve during the compression stroke, and very high EGT due to burning gas exiting the valve during the power stroke.

Thanks in advance for the education.

Six cylinder continentals are very vibration smooth. I felt like I was flying a Lycoming 4- not rough, just not quite right. The mag check in the air AND on preflight was normal- same decrement on each mag becuase both are missing equally. Continental TSIO 360EB1Bs carry the factory CHT on #5. I had reduced CHT and could not make TIT rise above 1350 F at any power setting. On the way, it smoothed out and thermally normalized; after my fuel stop at Lincoln (Logan County AAA) the short hop home was marred again by same.

We pulled the plugs and replaced them. They were worn, but were wet looking (fuel). No difference. Mags checked good; hard to believe both harness wires are bad simultaneously. Turn the prop- hear the hiss (exhaust). Cylinder is being removed as we speak.