Spending idle time, gas choice, some oil.
Game: Read this plug
- Thread starter CarlB
- Start date
OK, so tell us why.
Well, all the good guesses are gone, so it's time.
Well, all the good guesses are gone, so it's time.
I don't see enough white residue as leaded plugs can build up.
Failed head gasket on an iron block?
It's a spark plug off a gasoline car. Not an oil drain plug.
Definitely small engine but can’t rule out marine engine. Likely water intrusion or OPE sat outside for years. The gap appears large but it could also be the angle. It has a relatively short insulator nose and thick electrode. Therefore, it’s likely from a low RPM engine and cooler running application. Durability > performance in this case. I say OPE (generator/lawn mower/trimmer) or small boat/jet ski. When do you plan to reveal the answer?
Edit: Just saw the 30k miles info. I now change my guess to a motorcycle that likely sat outside.
Edit: Just saw the 30k miles info. I now change my guess to a motorcycle that likely sat outside.
Color makes me believe it’s an oxide. My guess is water/meth injection because it’s more fun than other guesses.
Rich usually shows up as lots of unburnt hydrocarbons, in otherwords "black." Soot can also indicate the plug is too cold. I'm asking what specific attribute of this plug screams "rich" or "forced induction"You keep saying this. What do you mean - how we got there.? How do you think we go there? We looked at the plug?
The sum total of the input we received from you is a picture of a plug with 30K miles and indication that all the plugs look the same - ie its not likely a bad plug.
Could be a weak coil - if its an old car with a single coil. I sort of doubt it though. I think it would be black not tan / red.
Your taking all the fun out of this.
I hope this is not something stupid like you ran seafoam or paint thinner.
I think there is a touch of oil burning since the center looks pretty black and a bit wet. Soot from running rich usually has no sheen to it. It’s likely a combination of both oil and rich mixture.
Rusty colored stuff, I’m not sure but I heard high ethanol content can cause this sort of color, but I have no personal experience.
Rusty colored stuff, I’m not sure but I heard high ethanol content can cause this sort of color, but I have no personal experience.
Carburetor with the float stuck open and pouring smoke yes. I am assuming you didn't run it like that for 30K miles.
slightly rich or plug too cold wouldn't necessarily be fully carboned. Incomplete burn / residual unburned components. The color is approximately correct - possibly a little more red than tan and definitely some black.
What it is not:
Its not running hot
Its not running lean.
It doesn't have coolant in the combustion chamber - no chalky white.
Its clearly not running right.
Its not burning oil.
So whats left?
Either something strange - like you burned something that you should not, or it sat out, or whatever. Which if thats the case then this game is sort of foolish because if it could be anything in the world not normal trouble shooting, then its purely guessing - not diagnosing.
This is what I'm thinking too. Seen it in some of the Mopar performance groups with guys running Boostane.
Plugs were installed 11/16/2024.
Engine is an LQ4 aka 6L Vortec
Vehicle averages about 1800 miles per month.
Plug photo was taken at 155k miles, 31k on the plugs
Engine OCI is on average 3,854 miles
EGR was present for the majority of the plugs lifetime
The vehicle is mostly used for heavy towing
The engine runs in closed loop at all times, 14.68 AFR unless operating in lean cruise, where it dips into 15.5 - 16.7
The reddish hue is coming from gumout regane or techron. One treatment per OCI was performed due to valve contamination for the past 15k miles.
These plugs are EOL and were at the point of causing misfire.
Engine is an LQ4 aka 6L Vortec
Vehicle averages about 1800 miles per month.
Plug photo was taken at 155k miles, 31k on the plugs
Engine OCI is on average 3,854 miles
EGR was present for the majority of the plugs lifetime
The vehicle is mostly used for heavy towing
The engine runs in closed loop at all times, 14.68 AFR unless operating in lean cruise, where it dips into 15.5 - 16.7
The reddish hue is coming from gumout regane or techron. One treatment per OCI was performed due to valve contamination for the past 15k miles.
These plugs are EOL and were at the point of causing misfire.
EOL = End of Operating Life....had to look that one up.
Thanks for the new term.
Thanks for the new term.
So these plugs have been through ~8 PEA fuel treatments?
Wow I would not have guessed. What was the gap?
