Changed the spark plugs today...

Do these look normal? I had the dealership change the plugs (I had them give me the old ones).. It seems the NGK's are a little dirtier, one more than the others.

My truck has 50k on it, I bought it used with 37k, so I am not sure if the previous owner changed at the recommended 30k, do they look like they were? I am no expert. Just wanted to hear your opinions.

Thanks in advance for your help.

 

Looks like the ones installed from the factory to me.

 

If the other three plugs are Denso, then chances are the previous owner didn't change them and they are the original plugs. Toyota for whatever reason has half Denso and half ngk on the tacomas off the factory floor.

 

WTF!!!????

 

Factory Plugs and looks normal! You're good!

 

this...

and this

 

Thanks for all of the input guys.. So, I am guessing the consensus is that they were the originals.. With that being said, I am wondering if I am going to see increased fuel mileage? I typically have been getting 17.5 to 18 per gallon. I guess we will see if that will go up.

Other than chances of lost fuel economy, do I have anything else to worry about for letting plugs go that long?

 

They are what ignites the a/f mixture...they arent done once the cars started. Everytime a cylinder explodes is because air and fuel get ignited by a spark plug. If there isnt a proper spark then the explosion sucks

 

Not glow plugs, spark plugs lol operates all the time when the gasoline engine is running.

 

Every compression stroke gets a spark.....

 

4 Stroke Engine:

Suck - Squeeze - Bang - Blow


Suck = Air is drawn into engine cylinders via the valves opening up when piston moves downward from the crank rotating upon start up. Air is now present in the cylinder since it was drawn in and the piston will travel back up from inertia.

Squeeze = Phase where Piston moves up in the cylinder compressing the air and injectors spray fuel into the cylinder. All valves are closed at this point.

Bang = Spark plug ignites this Mixture of air/fuel sending piston firing back down.

Blow = Cylinder travels back up after moving down and expels all exhaust gases out again and starts the cycle once more. This stage, exhaust valves are open.

 

They look original to me. Even more worn out than mine were at 42K. My MPG didn't change when the plugs were replaced.

 

Yup, it's true. NGK on one side, Denso on the other. Mine was the same way. Being fair to their suppliers maybe? The Densos seem to hold up better.

 

Agreed.. The Denso's were definitely cleaner (see pic on original post). The dealership replaced with 6 NGK's.. I will change in 30k for sure next time.

 

Obviously the original plugs. I cant imagine anyone (other than Toyota) would put in two different types of plugs.
I could see it now, someone telling their parts guy "Oh you don't have six of the densos well give me three densos and three of the other kind."

 

why????

 

I changed at 30k miles. All Denso plugs from Toyota dealership. Didn't notice any increase in mpg. I also ensured the gap of the plugs were within spec. The plugs were pre-gap from Toyota double checked myself.

Not to be off topic. But I have new plugs and my rear diff changed out with Mobil synthetic. And still no improvement in mpg. Low fuel lights up at 296 miles.

 

wow