spark plugs and p0300

Been throwing a p0300 check engine code lately, and I needed the change out my spark plugs according the book.  Spent a couple hours at Jackie's using her garage to change em out.  This is what my plugs looked like when I pulled them out...





Most of the plugs looked like this, except for one plug that appeared to have some oil on the threads of the plug.  

I'm curious... is that oil normal or could I have something going wrong within a cylinder, also, could these plugs REALLY be giving me a misfire code? or should i be looking for something else wrong now?

How many miles on them bro? They really dont look that bad

28,5 on em... i know they don't look too bad, but they are dirty. Could use a shining and probably good for another 3 years. Here's all the plugs laid out and a close up of one of electrodes.

They don't look horrible. As for misfire code, could be a bad tank of gas.

Then that's a lot of bad premium gas from shell cuz I've gone through at least 5 tanks of gas since i started throwing the codes. I thought bad gas... but it seems unlikely. Unless i have some water in tank or something.

Where is the 16th plug? only see 15 in pics. in the top pic the bottom left plug looks suspect to me. Is that same plug in next picture bottom right? The darkness of the insulator below the electrode does not look good to me, see how the others are white or slightly grey even dark grey can be normal. Black is not normal. Did the dark ones come from the same cylinder?

Must have forgotten to add that 16th plug to pic. I did notice the slight carbon build up at the base of the ceramic insulators but didn't think to much of it cuz they all look generally the same. The discoloration on the threads and the appearance of oil on a few of them(one worse than the others) has me slightly concerned about possible clylinder ring problems or valve problems. I didn't keep the plugs in order of which cylinders they came out of. The one with the most noticeable oil on the threads was the plug directly under the oil filler cap so i thought possibly that could be the source although the coil pack chamber appeared clean as a whistle.

Do you put antiseize on them?
The dirtiest ones are probably the MDS plugs.
Also, are you tuned for premium?
Running premium all the time in an RT is cause for carbon build up unless you are tuned for it.
Even though Shell may be the best gas, it is also the highest real premium octane you will get.
I put premium Shell gas in this past week to reduce my power output in snow.
Run your finger on the inside of your tailpipe lol if alot of carbon reduce the octane closer to your tune or 89 if not tuned.

Btw those are how my plugs come out. I also thought it was oil on one but remembered i caked antiseive on the first few and reduced the amount in the last ones i did which were passenger side, drivers side also scared bout the oil but i think it is the antiseize.

Yuro wrote:

I put premium Shell gas in this past week to reduce my power output in snow.

??

My max btu's are reduced, thus the power output is reduced. Just like putting 87 octane in it, power is reduced. Run premium long enough, when you put in 89, you can feel a bit of pep. In an RT, SRT main fuel is 91.

well lets see
1) these were the stock plugs. If they put never seize on them from factory, thats certainly news to me
2) The car is made for 91/93, in fact, the book even recommends it. ( they say 89 is OK, but 91/93 is what is recommended and the car "tuned for"...
3) Tail pipes are perfectly clean, so there is no excessive carbon build up. So i know i'm not burning oil to excess amounts, what i'm seeing could be part of "Normal consumption"...
4) I dont see how you get less power with premium over mid grade, because truthfully, my car notices the second it fires up... the pick up is sluggish, the response is slow, the car even growls differently, as if it's telling me "What the hell is this shit gas you gave me..."

yuro, sounds like you were there for the beginning and the end of the lesson, but may have nodded off in the middle. Tom, I got nothing for you. Nothing jumps out at me seeing those plugs, does it drive ok?

Didnt know this was his first change. Thought all RT's are 89 recommended, 87 acceptable, hmmm...
Check out a btu chart for gas types.

car drives fine... feels like it fires smoother with the new plugs, which of course, is to be expected. Although, i did feel a little "small dicked" after wards when I got smoked by a Wrx on il-53 doing a 50-100 pull... It felt "sluggish" which I just credited to the poor quality 89 gas I had to put in the tank as the wallet dictated 93 out of the question....or maybe he just spooled up his turbo before launch hahah... or perhaps there really is something going on... I'm probably just getting worried over nothing here, ill get concerned when I start losing races to honda's and v-6 chally's and chargers hahah

also... if 89 gas is "more powerful" as you say.... why then is racing fuel 110 octane? If btu content was related to horsepower, why then do race cars use 110 fuel instead of a lower octane like 83 or 81? that doesnt make sense...

truthfully... there probably isnt anything wrong with my car or engine or anything and I'm just overly concerned over nothing. But Something hasn't sat just right with me from the day i bought the car. Something about the dealer driven 5000 miles before I got it that worries me. I dont know what they did to the car during the break in period, so I'm just afraid shit is all sorts of broken, even though everything is probably perfectly fine.

Tune and compression, i have an 07 rt, and from what ive heard so far, all 5.7s used 89. Ive now seen 2/3 posts about 2011-12 using 91.
Srt engines have higher compresion thus using the higher octanes better.

<<<<<<<<<<<<<   Notice the Year.......

Notice i said i thought all 5.7s used 89. I searched on your year specifically and learned something new, not all 5.7s are 89.

just clarifying.... I know my engine is slightly different from the engines in previous years. As I understand it, I have the first year of VVT (Variable Valve Timing) (hehe i technically have a Vtec)5.7's in the chargers (I believe challengers started VVT in 09 or 10?) the previous 5.7s were MDS (Multi-Displacement System) instead of VVT...

And im glad ive learned these newer 5.7s use premium. Never knew that before. Crazy.

Yuro wrote:

Do you put antiseize on them?
The dirtiest ones are probably the MDS plugs.
Also, are you tuned for premium?
Running premium all the time in an RT is cause for carbon build up unless you are tuned for it.
Even though Shell may be the best gas, it is also the highest real premium octane you will get.
I put premium Shell gas in this past week to reduce my power output in snow.
Run your finger on the inside of your tailpipe lol if alot of carbon reduce the octane closer to your tune or 89 if not tuned.

Yuro.

Octane does not have any relationship to power.....engine compression does...

What Does That Number on the Pump Really Mean?

fuel octane sticker
In the automotive world, there are many common myths, which are repeated so many times that, after a while, they eventually transform themselves into ‘facts.’ Unsurprisingly, many of these ‘facts’ have to do with gasoline, whether they be regarding fuel mileage, power possibilities or some other arcane aspect of the internal combustion engine. Gasoline can be a confusing topic, and it is easy to make assumptions about it that may seem logical, but which on closer examination, turn out not to be true. A perfect example of this practice can be seen with octane ratings.

What are octane ratings? Simply put, when you pull into the gas station and are presented with the array of different fuel grades that you can pump into your car, the numbers written above each button or nozzle indicate that particular grade’s octane rating. Typically, the range will run from 87 octane on up to 93 octane.

In the world of automobiles, it is tempting to associate higher numbers with higher quality. After all, more horsepower and more miles per gallon are a better thing, which feeds into our perception that more impressive octane ratings also equal higher performance. Gasoline companies understand this mentality and do nothing to dissuade drivers from it, labeling 87 octane gas ‘Regular,’ and 91 or 93 octane ‘Super’ in an attempt to reinforce this way of thinking. After all, since ‘Super’ is priced higher than ‘Regular,’ it’s in their best interest to convince as many people as they can that paying a bit extra means getting better quality gas.

Unfortunately, this is where the myth of what gasoline’s octane rating really means creeps into the picture. Time and again, people will be told that high octane fuel burns cleaner or more completely, and that it will give them extra power and better fuel mileage than Regular octane gasoline because it contains more ‘energy.’ These blanket statements are simply not true. In fact, the octane rating for gasoline has nothing to do with the amount of power locked inside of it – it actually relates to just how much a fuel can be compressed before igniting. The higher the number, the less likely it is to ignite under pressure.

Why would anyone want to produce a fuel that was actually harder to ignite once inside an engine? To understand the role that octane ratings and ignition pressures play in a motor, it helps to be familiar with the term ‘knock.’ Essentially, when gasoline is sprayed into a cylinder by a fuel injector and mixed with oxygen, engine designers expect it to remain there in vapor form until it is time for the sparkplug to light it up, causing the explosion that drives the piston down to generate horsepower. The timing of this explosion is critical, as gasoline that ignites too early causes ‘knock,’ which reduces engine output and efficiency and which, in worst-case scenarios, can actually physically damage an engine.

In most engines, knock is rarely an issue because the compression ratio – that is, the pressure that the air/fuel mixture is put under in the cylinder – is low enough that Regular gasoline’s octane rating is sufficient. There is absolutely no benefit to running Premium fuel in a standard motor, since it will never be able to take advantage of that gasoline’s higher knock resistance. However, more aggressive engine management schemes, especially those found in turbocharged or supercharged vehicles, can turn up the compression to a high level, requiring much higher octane gasoline to avoid knock.

How can you know whether your car actually requires Super gasoline or whether it can get by on Regular? Almost every vehicle will list the octane rating necessary to run it safely inside the owner’s manual. Some luxury or sportscars might even place a small reminder on the gas gauge itself stating ‘Premium Unleaded fuel only’ to make sure you don’t forget.

To wrap things up: no, you won’t see a power or fuel efficiency increase by running high octane fuel in an engine that has been tuned and designed for Regular gas, nor will doing so perform any extra ‘cleaning’ inside the motor. On the flip side, running low octane fuel in an engine built for Premium can increase the risk of engine damage and will certainly impact that unit’s overall performance. The next time someone tries to pass these myths off on you, you can try explaining to them how octane ratings really work – or you can just smile and nod, pay for your gas and move on.

Thx J, that reinforced what i was saying was at work so i couldnt find a similar explanation.
I need a better job
Cant wait for warmer weather im jumping tune from 89 to 93! Woot!

Thanks Jim....that was informative for me. Hope you are doing great.