Static/Squelch Noise in Radio

Have an unusual problem with a new radio, an ICOM panel mount. Nothing
wrong with the radio, but I'm getting a squelch/static noise at certain
times. It is worse when both mags are on and when the engine goes from
about 2200 rpm down to idle. It is less on one mag and practically
non-existant on the other. It sounds like someone is breaking squelch.
At idle, it will make the noise intermittently, increase as I increase
rpm and is worse coming down.

A radio-guy suggested 2 new "P-leads?" I wonder if he meant
capacitors, which is what the previous owner suggested replacing or
Spruce and Chief have mag noise filters at about $45 each. AmeriKing
has a DC filter for over $100. I ordered 2 capacitors for about 10
bucks each, but there are others for close to 50 bucks each. Anyone
have any experience with this stuff? I figured if I'm going to waste
my money, I may as well try the cheapest things first.

By the way, I'm bending the rules a little. I had the same model radio
in the experimental I used to own, but I sold it to buy a McCulloch J-2
certificated gyro. It has a Lyc O-360 and Bendix mags. Thanks for any
help on this.