Just developed a misfire with no error codes and limped home. Initially was an occasional miss when lugging at low revs but then happened throughout the rev range.
Did the standard plug and lead replacement and then noticed something odd inside the No.3 coil tube when doing coil resistance checks.
There was a generally duller colour to the spring metal compared to the others and there was a yellow powdery coating on the inside walls of the tube. I thought maybe a discharge creating ozone inside the coil rubber tube above the plug electrode.
I looked with a torch and magnifying glass and could see a thin metal whisker a few mm long sticking out from side of the wire spring which is a sure candidate for sparking through the side of the rubber shroud to the spark plug tube. The whisker was firmly attached and I had to break it off with a steel pick. I could not see any evidence of a burned hole or carbon tracking through the rubber.
Replaced that one coil pack and all seems good.
Did the standard plug and lead replacement and then noticed something odd inside the No.3 coil tube when doing coil resistance checks.
There was a generally duller colour to the spring metal compared to the others and there was a yellow powdery coating on the inside walls of the tube. I thought maybe a discharge creating ozone inside the coil rubber tube above the plug electrode.
I looked with a torch and magnifying glass and could see a thin metal whisker a few mm long sticking out from side of the wire spring which is a sure candidate for sparking through the side of the rubber shroud to the spark plug tube. The whisker was firmly attached and I had to break it off with a steel pick. I could not see any evidence of a burned hole or carbon tracking through the rubber.
Replaced that one coil pack and all seems good.
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