57k and half the Irridium plugs are eroded, half look good

I just took my 2010 Tacoma with the TRD supercharger into the dealer for a misfire. Turns out that half of the plugs had completely eroded electrodes and the other half looked perfect. I asked if the 3 bad plugs came out of the same side of the engine and they said they came from both sides. Dealer advised that it is normal wear since I am hard on the engine but I would think that would wear out all of the plugs, not just half of them. I suspect there is an underlying issue. Any ideas?

 

Here is a picture of one good and one bad plug that came out of the engine.

 

It happens. Especially in FI applications. Due to the unnatural charge of air entering the combustion chamber at all times, stuff is bound to wear quicker. Don't worry about it.

 

Thanks for the feedback. The fact that half are extremely eroded and the other half look almost new doesnt concern you at all?

 

That ain't right, and not normal.

 

No. Because you are close to 60k. At 60k they are going to look like crap, especially when you are forcing extra air which isn't being intaken naturally.

Either that, or someone pulled the plugs and "gapped" them at one point. Are you the first owner of the truck?

 

That looks bad

 

The fact that after 60k they are worn does not bother me.

http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp

What is troublesome is why half would be in really bad shape and half would not be as bad.

 

Any ideas as to what would be causing only half the plugs to erode? Dealer said they test drove the truck after installing the new plugs with the computer hooked up and everything seemed to be running fine. I would imagine their computer would see if a particular cylinder was running lean/rich, etc. Im at a loss...

 

I wish I could help. My knowledge extends to making sure they are gapped properly and installation, that's it.

Did you try a "search" to see if there are threads on the same subject?

 

Like I said. Were the plugs gapped? Are you the original owner. If you say yes and no in that exact order I could tell you why they look trashed.

 

Yes, I am the original owner. Supercharger was installed by dealership the day I bought it. The truck had about 150 miles on it when the supercharger was installed since it was driven up here from a dealership in Virginia. Plugs were just replaced by the dealership. I would have to assume that they checked/gapped the plugs on the newly installed supercharger as well as the new plugs installed this week.

 

Holding up a brand new plug against one with 60+K miles looks like a perfect example of a burnt out plug. The new one is Iridum the other copper.

 

Same exact plug. Both are Denso Irridium as specified by Toyota. The irridium is so worn out it looks like a copper plug.

 

Did you wait till 60k to change them or did you do it at 30k and now 60k?

 

I asked the dealer if I needed to do it as part of my 30k maintenance and they said they are good until 90k since they are irridium so I waited and it wasnt until I got a check engine indicator for misfires that I knew they needed to be changed.

 

Well when you rush that much air it is going to be more harsh on our plugs, I would switch back to copper plugs and change them every 30k but I'm not sure if copper plugs are run with the sc, also are you running high octane everytime like your supposed to?

 

Dirtier fuel with a S/C pushing more air... Higher combustion temps... Could explain the plugs eroding that much. Spit-balling, but seems logical.

 

None of that explains why 3 plugs are toast and 3 are not.

Correct me if wrong but your photo is of 2 plugs that came from the same engine for the same amount of time, right? Your picture looks like a brand new plug next to a total meltdown, was the other a good used one?