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Discussion Starter #1
Ok, first off, I know this is overkill, but I change my plugs every THREE oil changes, or about 9-10k miles. When I pulled them this afternoon, I found this:






Now, what would be causing these to look LEAN? 92 DX 220k miles on original engine/trans and FUEL PUMP. Injectors are about 40k old (about a year old...I put 40-45k on this car a year). Would this be an early sign of a failing fuel pump? Car idles fine, never rough, and always has the power avail. when I need it (to pass or whatever).. All the other times when I have pulled them, they've looked a reddish/orange color (i.e. normal). My milage has not been affected. I still get about 420-430 miles per tank (about 33mpg with or without A/C on).

Any idea what's causing this? They are gapped at 0.040. I just put 4 new NGK's in again also gapped at 0.040.
 

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whitness shows signs of burning coolants...so your burning coolants

leaking gaskets crack in the cylinder wall i dont know check it out asome more
 

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could be oil or fuel additives causing that. if they look blistered you could be running too hot ie lean. if its just ash deposits it could be additives
 

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Discussion Starter #4
My coolant levels are fine. It isn't losing/burning anything.

I use a "fuel injector cleaner" every now and then, but not often. Maybe once every 8-10tanks?
 

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Discussion Starter #6
From the looks of that, it appears it's running too hot/lean? (Obviously it looks lean on those plugs). They are the correct heat range though. I'm 100% positive. I'm just scratching my head on this one. I'll see what this set of plugs looks like next oil change.
 

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that looks more like ash deposits to me. seeing as how they're only on one side of the ceramic, i'd say that your injector cleaner is the cause. because the injectors are shooting the fuel into the cylinder, it is hitting the plugs, and only the injector cleaner is left behind on the plugs. i'd go an oil change without any fuel additives and see what happens
 

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Discussion Starter #8
Sweet. Will do. I'm hoping it's nothing serious, as my 6 has been good to me for many many years. I'd hate to get rid of it. :( (anything major and it's getting traded in on a ***ducks*** brand new Maxima SE now that I can afford it..but not until the MX6 gives me a reason to trade her in. :)
 

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ZFreak-MXSix said:
My coolant levels are fine. It isn't losing/burning anything.

I use a "fuel injector cleaner" every now and then, but not often. Maybe once every 8-10tanks?
Arn't you only supposed to use that stuff like once or twice a year?
 

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SixSick6 said:
Insufficient cooling, over advanced timing, or an intake manifold leak.
over advanced? are the NA's even supposed to be advanced?


Its not a headgasket, ive never seen a car run great, burn coolant, and have the same looking plugs on every cylinder. its probably not a motor problem at all. It'd be very hard to destroy a motor that evenly.

I'm going to have to agree with whats been said, sounds like the remains of the fuel cleaner. i wouldnt use the stuff at all. i dont really believe in mechanic in a bottle, but i do believe that stuff can cause harm. with new injectors i wouldnt think you'd need it much anways. Try going without it for a while and see how it goes.

I'd also do a fuel pressure test. sometimes these pumps get weak and cant sustain 38psi of pressure, only spike to it then fall to mid-upper 20's.

-Eric
 

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The plugs always looked like that on my LX (as well as the exhaust valves). I wouldnt sweat it as long as the car runs ok.
 

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Discussion Starter #16
In the past, they always had a reddish/orangeish color to them (i.e. "normal").. Never have I had them look like this which is why I posted this. I have used the additives in the past and the plugs have never looked like this. This is what sparked my "alarm" in my head that something isn't right.
 

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im having the exact problem on my 1st gen...

ive got the plugs listed on the NGK site , and they've come out looking lean,....

im guessing i have an intake manifold leak, or my fuel pump is getting on...
 

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Discussion Starter #19
Pulled the new plugs.... about 1200 miles on them now (To houston and back twice, plus reg. driving) and they look identical to the former pic I posted, yet the car ran fine, and I still was getting 420-450 miles per tank, 33-35mpg... with or without the A/C on. No overheating, no nothing... just driving nonstop.
 

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Discussion Starter #20
1500 miles, and still look lean.
 
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