New Plug Wires Arcing - 2nd thread
 

Does anybody have any explanations or recommendations?

I'm having almost the same problem as this one from 2004:

http://forums.pelicanparts.com/porsche-911-technical-forum/176874-new-plug-wires-arcing.html

But I want to get a fresh start on the subject since its been five years. This is what is happening:

1. In the dark I could see sparks jumping between the wires and the fan shroud. The sparks could be originating in the wires or from the shroud, I don't know. This was not a glow like I've read about. The sparks were discrete, irregular, and roughly 3 to 10 seconds apart. The wires were 2 year old Karlyns with ~3000 miles on them.

2. About three weeks ago, the Karlyn dealer replaced the wires with a new set but the sparking still occurs.

The sparks are so faint that I have to get about 1 foot from the fan before I can see them. My dad who has very good vision but is 73 can't see them at all. When I put my finger where the sparks are I don't feel any shock.

I'm starting to think that the cooling fan and shroud generate the sparks from static electricity. And that the wires are just a convenient path to ground.

If it matters, the car is stock, has ~43,000 miles, and has been very well maintained.

oly,
I had the same issue with my SC. Noticing 'arcing and sparking' with the lid opened at night, I ponied up the money and bought new wires for my car. Upon receiving these 'new' wires it was quickly evident that these were the OEM for my car... and not cheap. I fired it up that evening only to discover I had the same amount of 'arcing and sparking' as before - these were not faint, but rather pronounced. I was disappointed and confused... and out quite a sum of money yet the original issue still existed.

Sorry I am of no help but rest assured your problem is not unique (and I am still looking for an explanation for my experience).

Could be static electricity. Try grounding the fan and shroud and see if it still sparks.

i dont know if this will help, but what about grounds. check engine to chasis grounds and any others on the engine. clean all grounds.

If you are not having ignition problems--like misfiring--it is probably static electricity, as mentioned. Remember, there is a lot of voltage going through those wires in short intervals and unless the wires are shielded with a ground (like the older wires) there will be some electrical effects. Induction timing lights depend on this when the clip is attached to the plug wire, though it is not "static" electricity per se but it is reading the current through the wire.

Thanks for the posts everybody. I'm going to try docrodg's fan grounding idea. I'll post what happens.

I'd like to know if same light show would happen w/Magnecores?

maybe the spiral-core Karlyns are at fault?

Every plug wire induces induction. How it's controlled is the issue. If those Karlyns have issues cross fire isn't far behind imo. It usually happens further down the wire that the cap... but still, i don't know enough to say it can't happen.

I tried docrodg's fan grounding idea and the results are not conclusive as far as I can tell. Specifically, grounding seemed like it might have made a small reduction in sparks for a few seconds but then made no difference.

And the more I think about it, even if grounding consistently stopped the sparks or made them brighter, what would that mean? Either way, the sparks occur without grounding, so they will always occur in a normal driving situation.

I'm starting to think that I'm too ignorant to figure this out.