Spark plugs reading....

PugMonkey

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Can any of the brain trust help me to determine why cylinder 2 has ended up looking like this? All the colours look good but cylinder 2 came out with a growth on it.

Thanks heaps.

Ps, these Bosch plugs I put in quite a while back to experiment with performance and humbly forgot they were in there. No problem with performance but today was the first time I've had to service in a while.

Sent from my GT-I9305T using aussiefrogs mobile app

20171029_153637.jpg

I've gone back to copper plugs because I still feel copper is a better conductor.

 
Last edited:
trying to post a pick but it wont let me....


G'day,
here you go...

pick.png
 
Can any of the brain trust help me to determine why cylinder 2 has ended up looking like this? All the colours look good but cylinder 2 came out with a growth on it.

Thanks heaps.

Ps, these Bosch plugs I put in quite a while back to experiment with performance and humbly forgot they were in there. No problem with performance but today was the first time I've had to service in a while.

Sent from my GT-I9305T using aussiefrogs mobile appView attachment 101021

Looks like cancer...
 
Gratis? or Grazie?

I would think that the residue is the result of burning oil, so a compression test would be in order, but not necessarily definitive. In theory if compression is even on all 4, then the valve stem seals would be suspect, but I believe it is possible for the fault to be the oil ring alone, with no wear/damage to the compression rings, so no effect on compression.

Cheers

Alec
 
In my experience those 4-electrode plugs don't last long in a tired engine. They foul quickly. When my sister had an Alfa Romeo I found I needed to change the spark plugs at least twice a year.

Roger
 
My R8 plugs do exactly that when I drive long distances. I find I need to clean them every 5,000 to 10,000 km. First symptom is misfiring under load. The engines uses practically no oil, but for long distances I add the lead substitute in the recommended proportions.
 
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