Induction leak

[simtech]

I recently read a few articles about induction leaks. What are the primary symptoms and if not fixed soon what are the possible outcomes? Running to lean...engine failure...excessive fuel consumption..plug issues??? So on. Just wondering.

 

[MAKG1]

The real obvious one that comes to mind is that full rich won't be full rich.

Max power takeoffs at low altitude could be "fun."

If the leak is bad enough, the engine won't start because you won't be able to make a combustible mixture.

 

[bnt83]

Higher than normal idle RPM.

 

[Chip Sylverne]

Look for blue stains in the area of the intake runners.

 

[Sleepingsquirrel]

Hey! I flew the Mooney yesterday and something happened at 6000 feet. I knew something was wrong but was seeing nothing I could really put my finger on. In flight mag check, ok. Carb heat seemed to help but then not so much. Mixture more rich helped but then not so much. Increasing the RPM helped smooth out the vibration. Low Rpm to descend made me think possibly that I had lost a prop tip. I flew the airplane to home port and landed and exited the runway with a badly vibrating engine. Run up at the tie down made the vibration go away but when RPM reduced vibration came back.
I tied the thing down thinking that it was a probable intake/exhaust valve sticking .
This morning I went back with the intent to run it and then find the cold cylinder. I found #4 was cold. Then I found this. Surprise! induction leak.

 

[Silvaire]

An intake leak is mostly going to effect idle and closed throttle situations and is going to have minimal effect when at high power when the throttle is wide open or close to it.