OEM spark plugs at 180,000 miles

That is a classic example worn out spark plug that's not a little ware. It was burning fine due mostly to the ign system being able to jump the excessive gap. You were lucky it did not trash the coil packs

 

I wouldn't worry about it but maybe think about it as your 100k or 120k maint schedule.

 

OEM plug on a lot of German cars.

 

^^^ This. That is definitely a worn electrode and a wide gap. It does appear to be burning clean though, which is surprising.

 

I have a feeling they might be for a 2nd Gen Tacoma that calls for a traditional Denso K20HR-U11 changed every 30K.

For those who haven't noticed this in the warranty guide, plug change is required at 30K to maintain emissions warranty. I'd bet a buck a dealer would tell you to take a hike if he found a set of those fancyschmancy Bosch plugs in your engine.

The following is item 4 at the bottom of the 4.0L 30K maint. schedule.

Maintenance services of spark plugs are required under the terms of the Emissions Control Warranty

 

I am Surprised that you can easily remove the spark plugs after that long / heating/cooling cycles. I hesitate to wait until the 100K per Toyota ....

 

To revive a very old thread, I’ve found my self in the shoes of the OP with my 07. All of the spark plugs I’m looking at putting in come Pre gapped and recommended for the specific year/ make/ model and all that goodness. None of the gaps match up with the .044 manual specs. Is this an issue or should I just plug and play with the recommended pre gapped bubbas?

 

I did similar recently, denso one side, ngk other. 230,000km. Had a headgasket issue unrelated and I couldn't believe the plugs I found.

 

Did they work out for you without adjusting the gapping?

 

I replaced mine at 100,000 and again at 200,000. It ran no better or worse after, but I'd think 180,000 on one set is pushing it.

 

Factory service manual spec range is .039" to .043" and is also what's stated in the TW Spark Plug Change How To thread. What do your gaps currently measure?

 

All the ones stocked at the local advanced are .044 and up. I’m not typically one to sweat .001”, but reading a lot of posts on here it seems that it may be worth considering for spark plugs. The best option may be a part purchase straight from the dealership…

 

That was my findings as well.
Mine were close .044 to .046

I didn’t adjust any of them. I stuck them in and ran it.
There’s a right and wrong way to adjust a plug. And I didn’t have the tool to do it “right”.
And if you are wondering, beating/tapping the ground strap (electrode) isn’t the right way.

Have I done it that way? Yes.
Did I have any problems doing it that way? No, not other than getting the gap too small.
But now I know better, and I couldn’t get away with doing that now. (Ignorance is bliss)

 

stick ‘em in the vise and set the gap about halfway up the blade of an old Craftsman screwdriver…



worked fine in the ‘75 LTD Wagon.

 

I miss those days

 

As long as it looks “close”, Right?

 

Me too

 

I used to fold a Juicy Fruit wrapper twice to set the points on my Tempest…

 

Matchbook cover is about .026 to .028

 

and the striker strip scuffs up the old contacts nicely…