RV-4 flying noise

Hello
Have this rattle noise in our RV4 like metal on metal type of noise which comes and goes with throttle changes. Has anyone else experienced this, will look at the front and rear control stick sections as well as the rudder too. Just a little disturbing.

Check the sealing rubber strip on the wing root fairing; especially at the bottom termination. Pretty common.

Look outside too

I had this on my 4. Take a look at the exhaust for possible contact with the engine mount.