Why do my Spark plugs look like this?

[GrantD]

I just pulled out my spark plugs today to have a look at them and was really shocked by some interesting crap on them. The stuff caked on there is kind of a tan/gold color. Some of them had a white coating on the electrode aswell. The tan/gold stuff is caked on the electrode and the porcelin both with usually a thicker gob of it on one side of the electrode. The further i got from the front of the car the worse the sediment was. The first one was mostly white while the last one was the worst actually having stuff bridging the electrode.

This crap wouldn't surprise me that much if the pluggs were 10 years old but i replaced them almost exactly a year ago and my car wasn't driven between september and april. Do you have any idea what would cause this on my plugs. Sorry the pictures are a little rough, i'm still figuring out this camera.
The plugs are autolites if it makes a difference.

 

[Anonymous]

im not certian but it looks like your gonna need a hotter plug. i think those look kinda burt. What type of gas are running, whats ur timming set at, is your carb adjusted.

wes

 

[GrantD]

I usually run 87 or 89 octane. I honestly don't know about the timing or the carb. I need to figure out how to do this. I tried to time it once with an older friend that knew what he was doing (but he's a v8 mopar guy) and we couldn't get it timed I don't remember what the value was but we had to retard the light drastically to get the timing mark to show up. I hope this helps some. I've got a lot to learn. Thank you. -Grant

 

[GrantD]

another thing that i thought of... Is it possible this is from my plugs not being gapped far enough. I checked one of the plugs and it was at .45

 

[addo]

I have seen some ugly deposits on plugs in recent years, simply from additives in the fuel. Lack of lead makes reading plugs harder, save for when they are obviously oiled up.

You could experiment a little with gapping and fuel type, then monitor the appearances obtained. If you get a deposit like that - but are showing best mileage readings, no overheating, then it may not be anything to worry about.

Cheers, Adam.

 

[LaGrasta]

honestly, the color is correct. spend .69¢ per plug, gap 'em correct and reinstall. Call it a done deal. I know it seems overly simple, but I think bad gas deposits, not driving the car for long periods, etc are easily overcome with just a new plug.

 

[S2261]

Sure looks like a fuel additive related problem. Any Haynes service manual has a color page of spark plug conditions.

 

[Lazy JW]

That isn't really anything to get excited about. Most likely caused from fuel additives and not driving far enough to burn them off. You could try some plugs ONE heat range hotter but I would be cautious there to avoid pinging. Just do a good tune-up and keep driving.
Joe

 

[GrantD]

Now that I Think about it I did at two different times put a bottle of fuel system cleaner through there...do you think that is what it is? I cleaned up the plugs as best as i could, they're still discolored but I got most of the build up off of them, would you recommend replacing them or should I not worry about it?

 

[rickwrench]

They are called "scavenger deposits" (for some reason). The plug temp is fine and so is the gap.

The additives that cause them are included free from the refinery.

Pull the plugs every six months or so and clean the crud off the electrode, gap, and reinstall. You had some fair sized globs in the pics. I pulled my plugs about three (?) months ago. the globs were HUGE. On a few plugs the deposits were bridging the gap completely.
Rick(wrench)

 

[GrantD]

Thanks Rick I just wanted to make sure it wasn't a sign that i was doing something wrong. So those deposites are from the gas?

 

[rickwrench]

The deposits are from -additives- (i.e., crap) in the fuel. Funny thing, the additives are supposed to help prevent misfires. Any kind of misfire kills emissions results. So, it's likely the additives actually do keep the engine from misfiring a little, when the plugs are new, six months down the road, the car is in the hands of the new owner and tough noogies.
I could get political here and say that this is another instance of muddleheaded legislators trying to "do something" without having a single clue what the heck they are doing... but I won't mention that.
Rick(wrench)

 

[Anonymous]

I could get political here and say that this is another instance of muddleheaded legislators trying to "do something" without having a single clue what the heck they are doing... but I won't mention that.
Rick(wrench)

Yeah funny how many mechanics work at the EPA. I for awhile had a Monte Carlo that when it would pass testing got a whopping 11-12 MPG. I moved to a non testing area and removed the emmision stuff, added headers, Edelbrock intake with out EGR and a big ol 4bbl square bore and a couple other goodies and it got 25MPG. But it wasn't "enviromental friendly" any more.

 

[CobraSix]

I could get political here and say that this is another instance of muddleheaded legislators trying to "do something" without having a single clue what the heck they are doing... but I won't mention that.
Rick(wrench)

Yeah funny how many mechanics work at the EPA. I for awhile had a Monte Carlo that when it would pass testing got a whopping 11-12 MPG. I moved to a non testing area and removed the emmision stuff, added headers, Edelbrock intake with out EGR and a big ol 4bbl square bore and a couple other goodies and it got 25MPG. But it wasn't "enviromental friendly" any more.

my 65 gets better emissions then my 99 mustang with a 3.8 V-6. Same mileage. hmm...all I get with all the technology is the ability not to repair the car myself.



To the original question. Again, color looks fine, just got some additives in the fuel. Switch gas stations (no mom and pop places), clean and regap the plugs, and you should be fine.

Slade