I suppose I am getting fully immersed into the joys and pains of ownership.
Just completed the annual on the 180D. Went smooth. No issues minus a carb replacement. All compressions were 75+. Engine is just at 700 hours and flies regularly.
I took 2 x 1 hour flights after the annual to mainly test the carb. Everything was perfect.
Last Sunday, I flew to Knoxville (160nm). No issues. On the way back and at ~30 nm from home, I start hearing a metal to metal knock. Moves up and down with RPM. No power loss. No heat spikes.
I landed without issue and on taxi the noise was more pronounced-likely from the lack of wind and/or it was getting worse or both.
So, into the hangar it goes.
I have a friend come over and we start trying to track down the noise.
You can hear it after each revolution and it seems to move to every cylinder. I say this because I thought it could be a broken guide spring or piston slap.
Pulled the valve covers off and nothing odd. Springs are fine. Rockers are fine. Pushrods seem to be fine-you cannot hear/feel anything on the pushrod covers.
No metal on the dipstick. Going to pull and cut the filter next.
The noise is like something is binding and then popping. It almost like when a mag disconnects (if you have ever timed a mag) but not as loud.
I can fee the pop/noise on the right side exhaust manifold for a couple revolutions but then it goes away as the noise seems to move from one cylinder to another.
I have worked on a lot of engines and I have heard failures from rods to piston slap and I have never heard anything like this. It is like something is stuck/out of tolerance on the cam or crank.
Any ideas?
Yes, I will have my AP look at it. But he is gone until Saturday and I am interested in hearing from those that are mostly hands on with their O-360
Any assistance or insight would be greatly appreciated.
Thanks all.
