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2009 M50

I was idling my M50 last night to let it warm up and flow some gas because it's been sitting too long. Once it warmed up I could hear a small crackling sound. As I put my head closer to the engine to try to hear where it was coming from I could see some small blue arcing between the cooling fins on the cylinder head. It was jumping from the spark plug boot cover to the fins. I could see it because it was dark. It was doing it on both plugs (both front and back cylinder heads). What does this mean? Bad plugs? Bad spark plug wires? Bad ignition coil? Any help is appreciated.

(I've googled searched this and searched the forum for this issue with "arcing, spark plug, spark plug wires" and couldn't find any existing posts.)

Thanks,

Heath
 

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Most likely it's the boots.
But if they are molded on the wires, you might need wires too.
And if the plugs are old or age unknown, it would be good to replace them too.

A dose of Berrymans B12 Chemtool in the gas would be good while you are burning out the old gas.
Unless it has stabilizer in it already, in which case put the B12 into the next tank.
And NO SeaFoam is not the same thing.
 

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It may also just be a build up of condensation on the plug cap/cables which will evaporate once warmed up. This is one case where WD40 is reccomended.
 

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It may also just be a build up of condensation on the plug cap/cables which will evaporate once warmed up. This is one case where WD40 is reccomended.
Indeed.
However, very often when the arc'ing occurs more than once or twice.....which is almost always.....a carbon chain of burnt rubber develops and the spark follows that.
Then the only good fix is new boots/wires.
 
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