windtzu

2008 automatic trans Honda Element - replaced plugs NGK Iridium at 108k miles

All plugs normal except one cyl/plug #3 - ash deposits.

Showed mechanic. Advised me to look at them at next oil change.

Pulled new plug at 3800 miles - number 3 has light white ash on electrode but on only one side.

There's also carbon glazing in one side of the insulator and rim of plug as well.

Car uses some oil, light @ 1/4 quart and sometimes just a little more every 3-4k miles. However, I have an oil bearing seal that's leaking, so there's no way to determine if the engine is using any appreciable oil, if it is at all.

Makes sense to do a compression test to determine worst case scenario - rings, etc. Will have the mechanic look at it.

Mechanic has his own theory: "The fuel injector for this cylinder isn't "spraying" properly. This may or may not account for the white ash deposits however. My understanding that they are either from oil, but can be from engine additives.

Given the new plug has deposits on only one part, and this is my theory, then I'm am I most likely looking at a leaking valve seal?

Thanks!

VegasInvasion

swap two of your injectors and see if the problem follows the injector. otherwise, most likely a valve seat issue, bad head gasket, or worn piston ring.
PS this isn't a tuning topic, I'm moving this to the proper category. Please read the forum rules before you post.

windtzu

Step one, the easiest in the process of elimination: Will try swapping the injectors, thanks!

You mentioned a possile bad head gasket. Since I haven't used a drop of coolant since I owned the car from 38k miles till over a hundred now, is it possible that bad gasket can produce an "oil leak" only without coolant. Btw, the coolant's been changed since and looks clean - free from oil.

While underneath the car, I did notice an oozing of what appears to be oil in the exhaust manifold area of the cylinder in question. When I rub it with a paper towel it looks and smells like oil. It's something I noticed when I performed my first oil change when I originally bought the car. As I said, it's small-minor and hasn't changed since. But I don't know what would be causing it.

Btw, wasn't sure how to categorize this post. Thanks for the correction.