97 5.7 Wires Arcing At Plug, All Ignition Parts New. ?

Doit · June 11, 2008

I just recently purchased this truck 97 K1500 350. 124,000 miles It runs good maybe a little week, but no driveability issues, It runs a little rough at idle, so I put in new Plugs,(NGK) still idles a little rough. I take a look under the hood at night in darkness to look for ingniton arcing, and found most of the cylinders arcing a little intermittenly where the boot meets the plug.

So i replace the wires,(Magnecore) still arcing on the same cylinders, I never seen this before, I check the cap and rotor they look fine but replace them anyway,(Napa's Brass cap) I take the time to make sure all is installed neet and tight, Now arcing is even more noticeable and brighter.

Any Ideas or suggestion?

95Sierra2500 · June 11, 2008

I'll bet the problem is you didn't put dielectric grease in the spark plug boots. I've never seen a plug wire come with enough dielectric grease in the boot, and have ALWAYS had to add more. Now that you're carbon-tracking on the plugs (the result of them arcing), it's hard to get them to stop without replacing the plugs. You can SOMETIMES clean the plug enough and put enough dielectric grease in the boots to make it stop, but you're better off replacing the plugs and adding dielectric grease instead.

Doit · June 12, 2008

I did put grease on the wires maybe not enough but, funny that the manufacture of the wires recomends no grease, I supose its possible I purchased bad plugs.

I don't drive the truck much only for pulling the boat and trips to home depot.

I figure right now the plugs are the problem, we shall see. Thanks for the input.

GMTRUCKTECH · June 12, 2008

I did put grease on the wires maybe not enough but, funny that the manufacture of the wires recomends no grease, I supose its possible I purchased bad plugs.
I don't drive the truck much only for pulling the boat and trips to home depot.

I figure right now the plugs are the problem, we shall see. Thanks for the input.

Doit, I know your not gonna want to here this but put FACTORY cap, rotor, ignition wires and spark plugs back on and I'll bet my house that it fixs it! I see it all the time in my shop people try to save some money by putting aftermarket ignition parts and have the same problems you got. Trust me on this one. good luck