"David" wrote in news:Wpitn.580013$DL1.346763
@newsfe25.ams2:

The one that I have used is the acetic acid cured silicone.

Then it is corrosive on aluminium. The galvanic currents created may be
causing or contributing to your noise problem.

I would be removing the stuff, difficult as it is to do, but if it is in
contact with metal, it is not suited to your application.

Owen