Pulled spark plug - how does it look?

Measure the gap which should be 1 to 1.1 mm. It seems that the gap on the pictured plug may be greater than that.

 

Hi Anthony. The tip looks fine, but I can't really judge the gap very well from the photo. I agree with Patrick that it does look a little wide.

I'm also a bit concerned about how you could get that much corrosion around the washer/gasket in 10k miles ? Was there noticeable water in the igniter well when you pulled it?

 

I'm not 100% sure that the gap is too wide, though it's a little hard to tell from the photos. The thread pitch is 1.25mm and when I zoomed your first photo it looks like the gap is definitely smaller than the thread pitch, so it could be ok.

 

Judging by the rust and the gap, do you really think that these plugs were changed at 120k? I would be somewhat suspicious that they only found their way on the invoice but not into the car itself.....

 

Those are the original plugs. I've looked at a lot of spark plugs from a lot of vehicles in my time. You were scammed on the plug change, perhaps on other work performed at the 120K maintenance as well. Time to go back to the dealership and confront them.

 

Great price on the iridium spark plugs.

I suggest you check the gap of the new plugs and set to 1 mm as needed. Usually a new plug will have a wider gap than that.

 

Your math is wacky. You say the doc's say they were were replaced at 119K and its now at 122K. I'm no accountant but that's only 3K miles on those plugs. They should look mint since the engine probably only ran for 1500 of those miles.

Those look like the original plugs to me. Pull them all.

Don't like all that rust either. Look real good in the plug wells with a flashlight and look closely at the connector on the igniter end too.

Show us a picture of the entire plug.

 

I would find it very hard to believe those plugs were changed. Especially with all the oxidation on them, it would need to be parked in water or something.

As to the engine sound, it is "sort of" like a diesel from the outside of mine and the engine up except much quieter. But I know what you are talking about. I would say normal.

And a slight hijack: I have heard many recommendations of anti-seize lubricant on the plugs before installation. Is there a gold standard recommended?

 

Hi Anthony, roughly what's the time interval for the last 10k? Like I said above I was most surprised to the that much corrosion around the washer/gasket on those plugs.

 

i still have an old spark plug sitting in my center console... it doesn't look that clean at all.. there is no white... all metal is the same shade... etc.. that one doesn't look like it has 100k+ miles on it (i was a bit surprised at how rough they look new... i thought it was all wear on the old plug)

your threads don't look too bad (mine had baked on goods)
that "rust ring" looks shiny and smooth like it was oil or something that somehow got baked on... the rust on the threads.. well... shrug
there is anti seize on it still.. mine had very small amounts left and it almost seemed cooked down (lack of better words)

i'm not saying "don't change your plugs"... you picked them up for an excellent price. (almost too good)

 

The spark plug model is used in multiple engines. It really is worthwhile to verify the gap with the correct wire gauge. You cannot adjust the gap on a used iridium spark plug, BTW, as that risks the side electrode weakening and breaking off after the used plug is reinstalled.

The sound is normal, the Prius engine sounds like a sewing machine.

It would be OK to use a very tiny dab of antiseize lube on the new spark plug threads. I just bought whatever was available at the local discount auto parts store.

 

Looks worse than mine pulled at 113k miles. I put one new Denso next to the stock NGK plugs.

 

When plugs are from Toyota in a Toyota box, or in a new car, they are NGK? didn't realize that thought they used Denso.