Spark Plugs Red Electrodes

[jackvine]

Change my plugs yesterday and noticed one side had red electrodes and the other side wasn't ! what could that mean?

[logray]

Red or purple deposits can indicate fuel additives. Actually all of them appear to have a little bit of red to them. Google "how to read spark plugs" for more info.

If it were me I would change the plugs, and pull them again in a 1000 miles or so to inspect.

Are you using any additives in the car (fuel or otherwise?).

Edited December 31, 2011 by logray

[JFP in PA]

A brownish tan to light grey color is indicative of a slightly rich than normal combustion condition. Darker colors (dark brown, grey, or even sooty black) indicate a possibly slightly over rich condition on that bank.

If the color change is limited to one bank only, I would be looking at potentially “aged” O2 sensors on that side (it is highly improbably, but not impossible, that all three cylinders are suffering injector issues or some type of oil leakage simultaneously). Fortunately, testing for aging O2 sensors (they become “aged” when they lose their response rates, causing the air/fuel ratios to go slightly out of range) is a simple task using a PIWIS or Durametric system, which can quickly pinpoint which sensor(s) need to be replaced.

[jackvine]

Well I discovered when looking at the car, that the 3 that are sooty are from the side where the gasket from Manifold to cat is leaking !Possible why it was running rich!

Ive not put any additive in, but Ive only had the car for few weeks so not sure what previous owner has done!

Also 4 coil packs were totally cracked so have replaced all 6 and the plugs ! Will look to see what happens in few thousand miles!

Edited December 31, 2011 by jackvine

[jackvine]

And these are the other 2 !

[JFP in PA]

That is pretty nasty........... Good find, however.