WD-40 is a lubricating oil. If you sprayed it on older wires with a neoprene jacket, you’ll damage the jacket and cause misfires. If the wires have a silicone jacket, it won’t hurt. ….but it certainly won’t help.
There is NO reason to ever spray anything on spark plug wires. If you’re having wet weather problems, buy new wires. Period.
It will help the wires to repel water which is a common source of problems. Breakdown services often do this when eliminating causes of breakdowns. At least, that used to be the case with older cars. I think new cars have more water resistance designed into their electrics so the old WD40 trick is needed less often now.
Well I watched my brother in law pull a can of WD40 out when his car wouldn’t start.
drowned the ignition system and cranked it over….
well it did start,
and his thinking,
if you can call it that,
was more is better,
So he sprayed a load onto the running engine and whoosh!!
fire ball as high as his head!!
He jumped back about 6 feet and looked at me,
“what the hell was that!”
Almost the end of your car was my reply,
They’d get wet. Why would you want to spray anything on spark plug wires?
Why mess around? If the plug wires are that bad that they need to be sprayed to stop arcing it’s time you replace them.
you get a misfire. spark will actually leak out of the wire and that is a true term for the event. the loss of spark leaves you with a miss.
WD-40 is a petroleum lubricant. Petroleum rots rubber products. Pure Silicone Spray does not damage rubber hoses and insulation.
You will be destined to live on Funk and Wagnalls door step for eternity. I mean what kind of cockamamie question is this anyway,I think your brain is rusty from lack of use….
It will displace any water on them. It will evaporate quickly as the engine warms to operating temperature.
DONT! It is VERY FLAMMABLE and does NOTHING for contact! Use DIELECTRIC GREASE< but power wash engine FIRST with GUNK ORANGE! It can cause FIRE and burn up your engine bay quickly!