Joostem

The other weekend I replaced all spark plugs and ignition coils on my Cayenne turbo.

The old spark plugs all had black soot on them.
And only 15.000 kilometer on them.

Spark plugs Bosch
Ignition coils Beru

Engine has a slight vibration on idle when cold.

Picture of old plugs below.

Any feedback is appreciated.

Quadcammer

not the best angle to get a good look, but I don't see anything too concerning.

twodollardoug

The porcelain is what you should be looking at. Greyish tan is ideal.

RAudi Driver

Yes and those looks like they were pulled early.

Joostem

Took some more pictures.

well I decided to pull them because of the rough idle when cold. No faults by the way.

the soot made me wonder if my engine is running to rich?

twodollardoug

I think they look great. The porcelain is the right color and the electrodes are clean. Don't worry about that soot on the inside wall "around" the porcelain. The work is being done in the middle of the plug. The the "L" shaped electrode on the top looks good also. Good color. You are looking for erosion of the "L" piece. You are also looking for minute deposits of metal on the porcelain. Can't tell from the pictures so you will have to get a good look. A magnifying glass may help.

twodollardoug

From the pictures, I would say your air/fuel mixture is good.