This may not be of any major concern- but under low RPM - hearing a slight metal shimmy sound (hard to describe.. maybe if you rub 2 metal cymbals and rub them together sound?) does that seem normal? Or has anyone else experienced this? Lycoming engine. (Engine oil lvl is good, no metal found in filter yet)
I’ve attached a short video of the engine - let me know what you guys think? Can only hear it on low RPM and other structures around you (to reflect sound back)
Yeah it sounds like something is rattling. Not normal. I’d have it looked at for safe measure. I wonder if the exhaust pipe is a bit loose and it’s rubbing against the cowl?
I'm conjuring up something that looks like a broken and loose exhaust clamp rattling around on an exhaust pipe. YMMV.
I think he was being highly sarcastic, but maybe his cirrus hero friend should film the OP from formation to get a better feel for the problem.
I have done lots of diagnosis on a car forum, but noise, vibration and harshness problems don’t lend themselves to remote diagnosis. Someone needs to have access to the vehicle for that. Find a competent and experienced tech locally and investigate until you find the cause. This is an airplane. If it quits, you can’t just coast to the side of the road and call someone from your mobile phone.
That's what it sounds like, alright. Nice ring to it, just like the flywheel will do. There's a spring on the Bendix that makes sure it retracts and stays retracted, and that spring corrodes and breaks and the starter gear will vibrate forward and contact the ring gear, making that very sound. I've seen it before.
Keep running it and eventually something will break well enough that diagnosis will be easier! (Sarcasm)
Ha! Yes I do - but I like getting everyones feedback before some Schmuck tells me I need to overhaul the engine. As a first time plane owner this forum has been awesome. For the most part I get useful advice!
Check the exhaust and their mounts. I had a clanking sound (oddly, I could only hear it WITH the ANR headset on) that turned out to be a weld for one of the exhaust hangers had broke and the end of the pipe was flapping.
Maybe you need to find a mechanic that's not a schmuck or maybe you think all mechanics are schmucks.
Out of curiosity, why are you ascribing that squeak/squeal to the engine? You're rolling during the clip you posted.. is it possible it's brake- or wheel-bearing-related? Sounds more like that kind of thing to me than engine, but of course it's impossible to localize a sound in a vid clip.
There's a clear ring to it. Brake discs don't ring when calipers are on them. A squeal sounds different than this. Loose exhaust clamps will have more of a clunk. To get a ring you need something like a bell or triangle, and the lycoming flywheel makes dandy bell when the starter bendix is bouncing against it. If the camera was ahead of the airplane instead of behind the exhaust and prop blast we'd get a much better idea
You guys won’t believe it - I face palmed myself when I found out. It’s one of the screws right next to the flywheel - touching the flywheel.
That happens, and not just there. You need to make a note next to the screw hole: "short screw only." There are numerous places in most airplanes where too-long screws can cut into fuel or hydraulic lines, control system pulleys and sometimes the cables themselves, and electrical wiring. Some control surfaces can be fouled by screws sticking out too far. Last year we found a pair of aileron control system pulleys locked solid by long screws at the bottoms of the doorposts in a Cessna. Someone had drilled extra holes there to help retain the plastic cabin trim, and had drilled right into the pulleys, too, and the long screws did the rest. That makes for stiff controls and worn cables.
Update - so it was infact the starter bendix gear not disengaging - I was quick to post a solution with screws... smh So now I’m looking at replacing the starter and labor for associated work. Not bad considering that’s what I originally anticipated. Does anyone know a hangar in f45? That I could rent short term to do some work?
Do yourself a favor and ditch the Bendix unit for a lightweight SkyTec starter. Less weight, better cranking, and no more cranky Bendix drive. I nursed my Bendix starter for a long time, and finally got tired of having the Bendix pinion cleaned and lubed. It would pick the most inopportune times to stick. Nary a problem with the SkyTec.
The OP doesn't have to worry about that. He has the Lycoming. The Bendix setup on the Lyc has at least as much trouble as the Continental starter drive, and much of it is caused by mechanics oiling that drive, contrary to the manufacturer's instructions. It's not a sealed unit, and oil just make dust stick to it and it gets sludged up and sticky and can leave you stranded somewhere inconvenient. A Skytec starter avoids all that by using a solenoid to engage and disengage the drive from the flywheel instead of inertia as the Bendix does. The Continental drive can last until TBO without trouble, but if it does fail, it is expensive as you say. I encountered one that had its ball bearings fail and If I remember right it was due to corrosion in an engine that was old and wasn't operated properly. Had to remove the accessory case and pan to find all the balls that got out and fell into the engine.
I do have access to a hangar at F45. A couple of them, in fact. But I am afraid that I would have to charge you my schmuck rate. https://www.pilotsofamerica.com/com...iper-warrior-metal-sound.119825/#post-2753200
Text me when you have the starter and I will talk to my friend with the hangar though I am sure that is not a problem.
Minor wear on the ring gear - had to carefully inspect to notice slight wear - safe to say, definitely not starting it unless I have it replaced.
Finally fixed the issue - Piper Warrior is back in flight! - ended up being a bad bendix starter - replaced it with a SkyTec Starter 149NL. Thanks guys for everyone's help - shout out to alfadog for the assist!
