Changed My Plugs Tonight…

And this is why we can’t have nice things. Spot the issue(s) here. Mind you, this truck has 167k miles.

I told her not to worry anymore. She’s in good hands now.

 

That's normal. 1st gens came from factory with 3 Denso and 3 NGK plugs as well

Edit - assuming that's what you meant lol

 

Do they really? What’s the reason for that? That is one thing I was pointing out. The other is that these look like they’ve never been changed.

 

They likely haven't been changed since it's NGK and Denso.

I don't think I've ever read an official reason why but it's well documented that's how Toyota did it. No idea if they do it that way for the 3rd gens, but they did for 1st and 2nd gen v6s

 

Most people just replace with all 6 of the same brand so it doesn't have to stay that way, but I'm curious myself why they came off the line like that.

 

Maybe @Empty_Lord knows why, he's a Toyota tech

 

Bizarre! I had no idea. Yea, I replaced them with 6 NGK Iridiums.

 

denso on one side ngk on the other. normal for the original plugs.. up to 2015 it was like this... why? no one knows.

even 2nd gen 4.0s did.

 

Why Iridiums?

The cheaper copper ones actually perform better as long as you replace them on schedule.

 

I don’t have a better answer other than it’s what I’ve always used. They’ve always performed great for me. Easy enough to change if I’m not satisfied.

 

Hey, at least you changed ‘em!

 

I hate it. My OCD hates it. Now I’m upset

 

Only use Iridiums if you have a supercharger. Per Toyota.

 

Some speculate that Toyota wanted to keep 2 suppliers happy and not single source one of them.

 

Seems like a quality control measure to continuously prove that the plugs are equal in performance.

 

Saw a thread here on TW that indicated Toyota has/had a stake in both suppliers and presumably wanted to spread the wealth a bit. I just picked up an 09 Tacoma 4.0 and also found original plugs with 123k. The gap on them was massive, truck ran ok, I guess that's a testament to the coils. I replaced them with Iridiums, seems to run fine, not sure why coppers would run better. Knowing I shouldn't have to touch them for many years is worth the extra few bucks - they were less than $40.

 

Iridium plugs in a 2wd…. You’re too good to it.

I’d be of a mind to tell it to just shut up and keep working. You’ll get new plugs when you learn how to drive up a slight incline on wet grass.

 

Yeah the gaps on the ones I pulled were about 2x larger than they should be. Mine was running a bit rough but not too bad.

Copper is more conductive so naturally better performance. That is a fact, but for some reason I’ve just always used iridium. They seem more dependable/better quality but I have no data to back that up. Mostly just an assumption.

 

The engine was designed to fire one bank on Denso plugs and the other bank on NGK's. This achieved maximum fuel efficiency in the 4.0L.






Just kidding.

 

Just wow.
Those gaps are huge.