Have Your Plugs Looked This Bad?

[Picasso]

I just changed my plugs and it is a good thing I did. In the 20+ years that I have been maintaining my vehicles (77 Chevy Nova, 90 Acura Integra), I have never pulled a plug that looked as bad as the ones that I just pulled from my truck. The smallest gap that I found amoung the eight plugs was .035. A couple were at .040. Additionally, there was no anti-seize used and they were not tight at all.

I can thank Toyota of Dallas for their condition since they installed them when I had the 30k maintenance done. I'm very glad that I'm doing all the maintenance at the 60k mark. When I changed my rear differential fluid, I had to tap the socket onto the fill hole bolt with a hammer because it was slightly stripped by the last person (Toyota of Dallas) to put a wrench to it.

I've attached photos of the plugs from two cylinders. Has anyone else's plugs looked like this when they were pulled? These two plugs are the worst but the rest are not much better. The tops of the pistons looked like what you would find on a grill at a public camp site. I'll have to try to fix that over time. Maybe a treatment with AutoRX is in order. I've done the throttle body cleaning with Seafoam twice over the past 10k miles which still didn't help the pistons.

I replaced the Denso K20R-U's with NGK BKR6EYA's (standard copper core) and the improvement in engine performance is huge. The first stop light that I came to after installing the NGK's, I thought that the engine had died. It hadn't done this but it seemed like it because it was so much smoother. The RPM's at idle have dropped as well. Hopefully my gas mileage will return to the level it was at before Toyta of Dallas installed the previous set of plugs.

[supritdeol]

My plugs were worse! when i bought my truck it had over 100k miles and i dont think he ever changed them. The truck felt 10 times more powerfull with new plugs and filters...

[hsvhobbit]

Yep..first plug change I did at 30K, most of them looked just about the same. When I did the next change at about 60K only a couple looked like that...That time I put in some long life platinum's so maybe they'll hold up a little better...That reminds me, I need to pull them since I'm at about 78K and see how they're doing.

[JeffD]

Those don't look bad at all, The factory plugs ground electrode is U shaped which causes the sides of the center electrode to wear faster. The trucks are also supposed to have iridium plugs from the factory, but my 2000 did not have iridium from the factory.

[Picasso]

Originally Posted by JeffD

Those don't look bad at all, The factory plugs ground electrode is U shaped which causes the sides of the center electrode to wear faster. The trucks are also supposed to have iridium plugs from the factory, but my 2000 did not have iridium from the factory.

The pictures attached to my original post don't properly show the colored deposits on the center insulater and the edge of the metal ground. The plugs showed signs of oil fouling and they also smelled as if that had happened.

I noticed earlier today that there are also signs of combustion blow by on the four center plugs (cylinders 3, 4, 5, 6). I've attached two photos showing this. It looks as if there was some leakage between the insulator and the metal ground of the plug, but I don't think that actually happened. Since it was clear that the plugs were clearly not tightened correctly when they were installed, I do think that blow by occurred between the threads of the plug and the engine head.

Has anyone else had their plugs look like this after removal?

Just another reason to do your own vehicle maintenance.

[KLS]

How many miles on those plugs?

I've used both the $1.59 Denso and NGK plugs, think I prefer the Denso, and have never had plugs look that bad after 30k. They do need the gap checked before installing, I always use a very small amount of antiseize on the threads, and use a torque wrench when installing.

The gas blowing out around the insulator is a sign of a defective plug.


Ken

[mustang67408]

These plugs have the typical signs of fuel additives. I am not saying your additives, but rather the GAS COMPANY additives. Those plugs look worn but not bad at all.

[Rlockyer]

Don't be too quick to blame them for improper torque.
This is an aluminum head, and especially if you are lubricating the threads with antiseize, it would be VERY easy to overtorque.
I've changed my plugs three times, and though I have not used a torque wrench, I've knocked 'em in there pretty good with my 14" ratchet.

The old plugs ALWAYS end up feeling like I could spin them out without the wrench.

[Picasso]

Originally Posted by KLS

How many miles on those plugs?

I've used both the $1.59 Denso and NGK plugs, think I prefer the Denso, and have never had plugs look that bad after 30k. They do need the gap checked before installing, I always use a very small amount of antiseize on the threads, and use a torque wrench when installing.

The gas blowing out around the insulator is a sign of a defective plug.


Ken

30k on those plugs. I gapped the new plugs and installed with anti-seize as well.

Originally Posted by Rlockyer

Don't be too quick to blame them for improper torque.
This is an aluminum head, and especially if you are lubricating the threads with antiseize, it would be VERY easy to overtorque.
I've changed my plugs three times, and though I have not used a torque wrench, I've knocked 'em in there pretty good with my 14" ratchet.

The old plugs ALWAYS end up feeling like I could spin them out without the wrench.

That's exactly how mine felt when I removed them. Maybe I shouldn't blame that one on the dealership. In another 30k I'll be able to compare my install with theirs.

Thanks for everyone's insight.

[Mike Donofrio]

Originally Posted by Picasso

Has anyone else's plugs looked like this when they were pulled?

That looks like quite a bit of oil fouling. I did my first set of plugs on the Tundra at like 90K and mine didn't look that bad at all. I had some glazing, some carbon buildup, and most of the electrodes were gone.

How does the engine run, is it rough? Do you use oil, do you have piston slap, etc?

[mustang67408]

Maybe this will help PLUG CHART

[Picasso]

Originally Posted by Mike Donofrio

That looks like quite a bit of oil fouling. I did my first set of plugs on the Tundra at like 90K and mine didn't look that bad at all. I had some glazing, some carbon buildup, and most of the elcerodes were gone.

How does the engine run, is it rough? Do you use oil, do you have piston slap, etc?

I agree about the oil fouling. The engine has always run pretty good, and runs even better after putting in the new plugs. I have never burned oil nor do I have piston slap.

Originally Posted by mustang67408

Maybe this will help PLUG CHART

That's a great chart. None of those plugs look real good yet some are labelled "good" and "best." Mine resemble #20 and #22. Must be OK.

[mustang67408]

I agree, i had picked out #22 myself. I wouldnt be to concerned about the plugs. I have see alot worse
the little spots/dots are fuel additi