Banging noises sitting still with parking brake applied

[jspringe]

I am sitting still on a dirt strip with my parking brake on and engine below 1000. I am hearing constant banging noises as if I was rolling down the runway.

Jason

[N6722c]

I am sitting still on a dirt strip with my parking brake on and engine below 1000. I am hearing constant banging noises as if I was rolling down the runway.

Jason

Take a look outside, at the exhaust. Do you see a puff of Black Smoke every time you hear that "Bang".
Is it the same "Bang" that you get when you go from 500rpm to 1500 rpm ??

[jspringe]

Yes, that may have been it. Cold start, low idle.

EDIT: Confirmed. As the engine warms, the idle knocks go away (except as you indicated when revving down from 1500+).

Jason

[N6722c]

Yes, that may have been it. Cold start, low idle.

EDIT: Confirmed. As the engine warms, the idle knocks go away (except as you indicated when revving down from 1500+).

Jason

Would be nice if we had the choice of 100 or 100LL when we filled up

[primeGT]

Hi,

Good to hear it has been resolved, as I was about to state that perhaps they have modelled a loose selt belt rattling around on the outside of the fuselage