One spark plug with Ash, what's up?

[fishEH]

Changed my plugs today all looked ok, like this.

Except plug #2, passenger front. Looked like this.

According to all the pics I can find on the interwebs its ash deposit, sometimes caused by fuel additives or cheap gas. The threads were also quite oily. Since its only on that one plug I'm thinking something else is up. I have also had a tick for a looooong time, as in years. And I have a high idle. No codes, but the EVAP and O2 HTR MILS won't set.
Any thoughts?

 

[jafir]

I vote you have a valve problem. Guide or seal?

 

[p m]

I had similar deposits on other vehicles that I attributed to coolant in combustion chamber.

 

[fishEH]

Both of those sound NFG. I did the heads(and a valve job) in Sept 2010.

 

[listerdiesel]

I'd tend to agree with coolant also.

Peter

 

[helievacpilot]

Ruh Roh!

 

[fishEH]

Could this be a slipped liner issue? I don't have any significant coolant loss, I just added about 1/8" into the expansion tank yesyerday but it didn't strike me as a big deal.

 

[DarylJ]

Could this be a slipped liner issue?

Without proper diagnosis it "coule be" damn near anything including that.

 

[Jake1996D1]

I bet it's oil but as Daryl can tell you I have known to be wrong before.

 

[fishEH]

Without proper diagnosis it "coule be" damn near anything including that.

I guess that's part of my question. How do I go about diagnosing.

 

[listerdiesel]

I guess that's part of my question. How do I go about diagnosing.

Get the car up to temperature, take out that plug as soon as you can get at it. Get the piston up to TDC and leave it for 24 hours. Then have a look in the plug hole and see if there is any liquid in the cylinder.

Peter

 

[singingcamel]

Usually burning coolant would show up as if it were steamed cleaned .what kind of plugs you using ?
Do you drive it long distance or just short runs ? bad plug . change it out ,drive awhile and pull it .

 

[carlosz]

possible a random misfire or weak spark to that cilynder, in combination with low grade fuel, stop and go driving, high chamber temps and additive use.... I would clean or replace, along with full tune up, then i would keep an eye on driving and fueling habits and recheck in 6k miles...if it returns I would begin with cylinder leakdown test, you have a little oil on it too. I would be inclned to think one of your valve springs is a bit weaker than others thus causing valve stem to ride a little high, this in turn causes early valve seal failure.
check your pcv as well make sure all hoses are in good shape.
if all ok I would not worry much. if at the six month recheck the issue has returned and cylinder leak down is marginal I would consider cylinder head overhaul...