IO-550 "pop" noise?

RyanB

RyanB

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A couple days ago i was out watching some airplanes land and i noticed an SR22 on approach, as the engine was idled it made a popping noise for a brief second and i didnt notice it after that. Almost like as he rolled out on final, idled the engine and made a pop sound. What could this have been? I havent noticed it before.
 
Happens in my O-360 when I go yo if ke on short final. Used to happen in a truck I had with a 351-Cleveland engine. Always thought of it as the sound of power ready to go.

<burble> <burble> <pop> <burble>
 
excess fuel that is not burned in the low power setting going out the exhaust
 
I assumed it was normal just not something i remembered hearing in the past.
 
Hank S said:
Happens in my O-360 when I go yo if ke on short final. Used to happen in a truck I had with a 351-Cleveland engine. Always thought of it as the sound of power ready to go.

<burble> <burble> <pop> <burble>
Click to expand...

Ok, I think I figured this out: yo if ke = to idle.
 
Ryanb said:
A couple days ago i was out watching some airplanes land and i noticed an SR22 on approach, as the engine was idled it made a popping noise for a brief second and i didnt notice it after that. Almost like as he rolled out on final, idled the engine and made a pop sound. What could this have been? I havent noticed it before.
Click to expand...

Too much fuel flowing.
 
Probably a ham fisted pilot, noticed 550s do that when someone goes from powering it in, to "uh oh, to high and or fast" and chops it.
 
Backfiring. Happens. If you immediately pull back on the throttle the fuel delivery system can't react fast enough to reduce the fuel flow causing the over rich condition. Reducing the throttle slowly will eliminate that. Some engines are worse than others for backfiring.
 
Sometimes the prop wash will cause an odd popping sound when taxying in a moderate wind. Everything has to be lined up right and it doesn't last long.

Anyway, I've noticed it on several aircraft I've flow- including the DA20.
 
My O-320 would never do it with a fixed pitch prop but with the constant speed prop if I adjust it to fine pitch and pull power to idle it will pop pop pop every time.
 
Ryanb said:
A couple days ago i was out watching some airplanes land and i noticed an SR22 on approach, as the engine was idled it made a popping noise for a brief second and i didnt notice it after that. Almost like as he rolled out on final, idled the engine and made a pop sound. What could this have been? I havent noticed it before.
Click to expand...

If it popped once it was your imagination, If it popped twice, that will be under $1000 to fix if it popped more than that it's an Awe****, cost to repair may exceed the value of the aircraft.
 
Richard said:
I vote ham fisted pilot. Not a smooth operator.
Click to expand...

Yep, I do that from time to time on the descent on my IO-360. I've been called worse. :D

At least I'm not the nutjob on the other thread who takes 8 seconds to open the throttle on a NA engine. What's next, V(n) callouts on our little tractor motors? Maybe some epaulets? :rolleyes: Piston GA can be such a bush league...
 
Tom-D said:
If it popped once it was your imagination, If it popped twice, that will be under $1000 to fix if it popped more than that it's an Awe****, cost to repair may exceed the value of the aircraft.
Click to expand...

Care to elaborate on that
 
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