Why after 10k miles are my spark plugs burnt?

My spark plugs are burnt on the ceramic part and only after 10k. Anyone have any answers? Is it running too lean? It runs great though. 01 prerunner 3.4l

 

Post some pics of them. What type of plugs are you running?

 

was the gap checked before install?

 

discoloration is normal, spark plugs won't look "new" after 10K miles. If it is running good as you say, the burnt you are seeing is most likely normal assuming its the right plug and gaped right as well.

 

Remember (not being sarcastic) there is an erratic spontaneous combustion going on there so...

 

What is you definition of burnt? They will not stay white after you use them.

 

Ya, would want to see pics. What made you pull them after 10k?

 

It's a dark amber color that's about a quarter inch wide right along the bottom most part of the ceramic. I already changed the plugs out. It only happened on one side of the engine. That's why I'm a little concerned. I know they aren't going to look brand new but the other side doesn't have a burn mark on the ceramic. I'm running denso f116's gapped at .40"

 

Do they look like any of the images on this site:
http://www.ngksparkplugs.com/techinf...q/faqread2.asp

 

If they are burnt very dark then you are running too lean, if they are a very light color you are running too rich. (I could have the lean/rich mixed up??) From what I was told, spark plugs should be right in the middle, not too light and not too burnt. With you saying that its an amber color I would say that it seems fine...

WAIT a minute,

"It's a dark amber color that's about a quarter inch wide right along the bottom most part of the ceramic. I already changed the plugs out. It only happened on one side of the engine."

here it sounds like you're talking about the top part that connects to the spark plugs not the part that is INSIDE the engine actually igniting.......Where is the discoloration?? Pics would def help!

 

the burnt ones came from the passenger side of the engine and the other side was completly clean

 

Subbed because my mind is blown right now.

 

^^This

 

That's what I thought you were talking about....very very interesting, I have never even heard or seen this before.... it looks like they are actually burnt, but I find it hard to believe that one side of engine could be that much more hot then the other to cause this..... hhmmmm

anyone know what kind of Current spark plugs can handle? Is it even possible for these trucks to put out something that could be harmful?

Do you have any mods on the truck? specifically dealing with the engine, intake, exhaust??

have you been running hot? burning oil?

 

http://www.toyotanation.com/forum/1...60033-oily-burnt-spark-plugs-pics-56k-ok.html

 

scroll down to the pics and the section..

What Happens When Plugs are Installed Incorrectly?
http://www.volvoclub.org.uk/faq/EngineMechanical.html#RemovingSparkPlugs

maybe all you did was over-torqued the plugs when you installed them?

 

OP, did they have any oil on them like ^^