Spark plug reading review
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From: Orlando
Spark plug reading review Ok guys so I updated my 41-906’s awhile back and here are the ones before the updated ones. These plugs have around 35k abusive miles on them and I want to get your opinions on what your readings reviews on them. I have a tough time reading them because there are lots & lots of misconceptions on how to read your plugs. So Id figure Id leave it to you guys with more experience. These are the driver side plugs as they are in order. First pic is 1, second pic is 3, ect. These are gapped at .050. Need info on if I need if I need injectors or temporarily clean them, get a re-ring kit (rebuild) burning oil, running rich or lean at WOT or idle, ect. I heard you can tell your timing just but reading your spark plugs. Now I don’t expect you to know every single detail. Just an idea what is really going on inside my cylinders. Second post will be most stunning on cylinder 2!!! 
spark plug 1-3-5-7
spark plug 1-3-5-7
Thread Starter
TECH Enthusiast
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From: Orlando
Now these to pics are of spark plug Cyl Number 2. What the hell??? Two cracks on the insulator what does this mean and should I be concerned or is it the plug wires themselves? I honestly never seen this before 
Thread Starter
TECH Enthusiast
Joined: Feb 2012
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From: Orlando
Anyone else have any input on reading the plugs themselves? Or am I running fine?
130+ views and some ignore. May not be an interesting rebuild post full of eye candy but hoping we have some good LTx advance teachers. Lol If I had to judge I am burning some oil while running lean at WOT. When I first got the car the original plugs were pretty black convincing me it was running rich. The 2nd set (which are the ones your looking at) have been driven hard for 2 years. The 3rd set I haven’t checked to see how their doing. Just want to know what maintenance should I look at next. It sometimes can be deceiving wether telling if I’m burning oil or running lean. A.I.R pump is deleted and what wondering if I’m running lean at idle.
I don't have the best understand about plug reading, and I'm sure someone with more knowledge on the subject will clarify... But to accurately read timing off a plug and stuff like that you can't really have any idle time on the plugs. For instance, it's more of a roll your car to to the start, run the 1/4 mi. and turn car off immediately after the run, no driving back to the pits or any of that. To recreate that scenario at home on da streets would be really tough... So especially at 35k miles you really can't read plugs like your talking about.
You can read temps and other obvious sings on plugs.
The ground strap is about the only thing you can read with out doing what formulajoe said. Take a look 1,4,&6 compared to the rest, the ground strap has carbon shading on the strap on those plugs were the rest dont have that much. The closer the shading is to the threads of the plug the hotter or cleaner the cylinder is burning. Oil ingestion or to much fuel can cause the temp to cool down and the shaded area will go from the threads over the bend and out towards the end. That being said you have to also know the orientation of the plug in the cylinder. For the most part as long as the shading is somewhere close to the bend of the ground strap that is considered perfect temp range.
Biggest thing you are looking for when you pull plugs is to make sure the plug isnt melted and that the basic shape of the plug has been retained and not melted away or broken off.
Make sure that there is no Aluminum material on the plug
Make sure its not oil soaked
make sure its not fouled up with carbon
It should look it's age in other words.
The ground strap is about the only thing you can read with out doing what formulajoe said. Take a look 1,4,&6 compared to the rest, the ground strap has carbon shading on the strap on those plugs were the rest dont have that much. The closer the shading is to the threads of the plug the hotter or cleaner the cylinder is burning. Oil ingestion or to much fuel can cause the temp to cool down and the shaded area will go from the threads over the bend and out towards the end. That being said you have to also know the orientation of the plug in the cylinder. For the most part as long as the shading is somewhere close to the bend of the ground strap that is considered perfect temp range.
Biggest thing you are looking for when you pull plugs is to make sure the plug isnt melted and that the basic shape of the plug has been retained and not melted away or broken off.
Make sure that there is no Aluminum material on the plug
Make sure its not oil soaked
make sure its not fouled up with carbon
It should look it's age in other words.
