Plugwire / radio suppression?

What makes plug wire "high suppression"? OT because this also happens to be a Nissan.... 2001 Xterra... It's running fine and not setting any codes... but I'm hearing a tick coming
through the FM reception. Sounds just like the tat tat tat (no whining) you get when a manifold gasket starts to leak, but definitely coming through the radio reception. My assumption is a bad plug wire?? I couldn't see any arching... of course, can't really see much on it.
Is it high resistance that makes it high suppression? Maybe one wire's resistance is too low (if it's not arching anywhere)? I'm going to at least check that all are fully seated on the cap and plugs. I'm wondering if there could be a break inside one of the wires so it's arching inside the wire itself?
I had it in for a brake job... wondering if I should be pushing for a tune-up based on this, or if something else can be causing the signal. It's definitely 1 tick per rev / changes with engine speed.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Try spraying some silicone waterproofing on the wires 1 at a time and see when (if) the ticking noise quits.
Ken
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.