- Joined
- Aug 21, 2010
- Messages
- 3,301
- Reaction score
- 1,000
Plane is down for annual right now. Cyl #4 failed compression check, and they identified the exhaust valve as the culprit. This same jug was off for the same reason 3 or 4 years ago (probably about ~200-250 hrs) for the same reason, and the valve and valve seat were repaired at that time. Engine has ~1000 hrs SMOH.
I asked my mechanic if there's anything I'm doing operationally that's causing this. He said that it's possible I was letting the engine run too rich. I generally lean out pretty good in cruise, but I am not always religious about it on the ground, especially after landing while taxiing back to the hangar, or in an extended wait for takeoff at a towered field.
What, if anything, should I be thinking about for a cylinder that's had a leaky exhaust valve twice in a relatively short period of time?
As an aside, I never noticed any issues with this cylinder from my engine monitor, at least in CHTs--cyls 3&4 trace pretty much the same line on the CHT plot, and both are consistently a little higher than 1&2. My #4 EGT sensor started getting erratic earlier this year, so it's getting replaced right now, but if there were any clues to be had from it they were lost in the ratty data.
I didn't see any clues from the monitor in CHT or EGT when the previous work was done to #4, either.
I asked my mechanic if there's anything I'm doing operationally that's causing this. He said that it's possible I was letting the engine run too rich. I generally lean out pretty good in cruise, but I am not always religious about it on the ground, especially after landing while taxiing back to the hangar, or in an extended wait for takeoff at a towered field.
What, if anything, should I be thinking about for a cylinder that's had a leaky exhaust valve twice in a relatively short period of time?
As an aside, I never noticed any issues with this cylinder from my engine monitor, at least in CHTs--cyls 3&4 trace pretty much the same line on the CHT plot, and both are consistently a little higher than 1&2. My #4 EGT sensor started getting erratic earlier this year, so it's getting replaced right now, but if there were any clues to be had from it they were lost in the ratty data.
I didn't see any clues from the monitor in CHT or EGT when the previous work was done to #4, either.
