spark plug wear; is this normal? (56K there are some big pics)

white out

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I did a spark plug change on my '99 ACR: catless, B&B cbe, and mopar wires (stock :dunno: ).

History:

It was a TX car for 18k, so 91 octane. I've had it for 5k miles and run 93 octane. I do not know the age of the plugs.

Plug 10 was in the worst shape, so it has the close ups.

Does this look normal, or like the car is running too lean/hot? There is some white, but all electrodes (except 10) are black.

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Thanks,
Nick
 

bluesrt

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look good to me/ some cylinders run cooler than other, like the last ones in the rear may run hotter
 

Russ M

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The wear looks normal but all the plugs look very lean.

Something else all those tiny little dots all over the plug are they pit marks or some sort of buildup, cant tell from the pictures.

When was the last time you change fuel filter? You have no cats, so what are you using to tell the computer that so the engine light does not come on? Has the computer ever been tuned? All of these things can cause a lean condition.

Last but not least these plugs are very cheap and wear fast, no reason not to change them every 2-3k miles if you want best performance out of your car.
 
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white out

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Thanks everyone.
The wear looks normal but all the plugs look very lean.

Something else all those tiny little dots all over the plug are they pit marks or some sort of buildup, cant tell from the pictures.

When was the last time you change fuel filter? You have no cats, so what are you using to tell the computer that so the engine light does not come on? Has the computer ever been tuned? All of these things can cause a lean condition.

Last but not least these plugs are very cheap and wear fast, no reason not to change them every 2-3k miles if you want best performance out of your car.

The black marks? All the plugs were knocked around in the box before the pictures, so some of the white soot has come off.

Never changed the fuel filter.
Car came catless, with no cels. No idea if the car has been tuned, I assumed stock tune since it's basically stock.

I have no problem changing plugs often, they really are cheap.

Nick
 

Russ M

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Nick,

The white specs all over the electrode/porcelain if they are pit marks then its detonation.
 

Olddudesrule

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Look decent to me, but slightly lean as most have said. Also agree with BluSRT that rear cylinders tend to run a bit hotter just due to positioning.
 
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white out

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Talking to a local that tunes Vipers. Since this car has seen many track days with the previous owner, wondering if leaded race fuel may have caused some of the build up.

Nick
 

Roy

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I wouldn't be happy if mine looked like that, they have to be the color of coffee with milk, yours look like milk only, this is not good.
 

ViperTony

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That looks lean to me. Also, when changing out the plugs, go with the SRT plug. RC12ECC

Others recommended this as well but what's special about the RC12ECC as opposed to the RC12LYC plugs?

Thx.
- Tony
 

Dom426h

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Have you put new plugs in her yet Whiteout?

my advice is to forget about the past as you cant change what type of fuel the previous owner ran and such.
Throw some new RC12ECC's in her and if the wires are original change them while your at it(the date is printed right on em)
Drive for a thousand miles, then pull em and inspect if your curious.
 
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white out

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Have you put new plugs in her yet Whiteout?

my advice is to forget about the past as you cant change what type of fuel the previous owner ran and such.
Throw some new RC12ECC's in her and if the wires are original change them while your at it(the date is printed right on em)
Drive for a thousand miles, then pull em and inspect if your curious.

I was going to wait a month then swap to the CC's. I'll update at that time.

Thanks for the info on the plug wires. I will take a look.

Nick
 

Jack B

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When you try to read plugs after being installed for a long time their overall condition is the result of your car's closed loop operation. You can always get a one or more fouled plugs due to a mechanical issues. Basically this means the general condition of your plugs is due to the operation of the O2 sensor system.

To read the plugs at WOT you have to immediately shut the engine down at the end of the run. You then have to view the area at the top of the insulator. That is the area inside the thread well. Due to the type of plug we have means you have cut the thread barrel off on a lathe close to the top of the insulator. On some plugs you can see that area with plug viewer, it looks like the instrument an optometrist uses. I have one and i have a hard time seeing that part of the insulator.

If you have a modded car and do a lot of partial throttle operation it is possible even with properly operating O2's to run leaner than normal. This is because VE of the engine has changed at certain points on the power curve and the factory injector pulsewidth map for load versus rpm is no longer correct. Running lean at light loads is not all bad, in fact most new daily drivers are set up this way from the factory.

As far as detonation, that typically results in mechanical damage to the plug such as missing or bent electrodes or cracked insulators. The precursor is a pepper like deposit on the insulator. That is actually the aluminum from the pistons being deposited on the plug.

I am surprised your plugs look that good with those miles.
 

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