What is this on my ignition coil? 150k spark plugs

Hello
Just finished changing my spark plugs for the first time .

5/6 look fine but on my passenger side middle spark plug I discover this on my ignition coil; What is it?

That spark plug also looked the worst out of the rest(bottom middle) . All other ignition coils are clean.


This is my 1st spark plug change at 150k
Never had issues with rough idle, starting, misfire, etc.


I put in the new plugs and everything is working fine. Should the ignition coil be replaced? Thanks

 

that’s blowback from a loose spark plug. You could try cleaning it up and if it doesn’t look like it’s damaged use it.

 

Almost looks like exhaust soot. Was the plug loose?

 

They usually look like that when the spark plug was left loose from the factory. So blow by.

I've personally seen multiple 3.5 tacomas with loose plugs from factory. Plus several stories here about it.

 

Thanks for the quick responses guys. Yeah I’m guessing at some point it was loose from the factory but it was definitely the hardest to get out. That thing was stuck from all the buildup. Threads were fine going back in.

 

Put those damn things back in there, they are good! 60K swap out interval is a joke.

 

I feel like these could’ve pushed 200k no problem had they been properly torqued at the factory.

All the ones I’ve seen around 100-120k in videos still looked fine ‍♂️

 

Should you put never seize no the plug threads?

 

I do but you have to be careful not to over torque them. It’s crazy how much torque it’ll add (or subtract?), something like 100%. So 7 ft/lbs on your torque wrench is actually equivalent to 14 ft/lbs if you didn’t have anti-seize on them.

I just get them snug and then do a 1/4 turn.

I’m not a mechanic though so take this advice with a grain of salt.

 

idk why they do 60k intervals. thinks its so incase people put basic copper plugs in. the modern double iridium and platinum plugs last a ridiculously long time.

 

Considering these have been in 8 years and haven’t seized I’d say it’s not necessary but ymmv. Denso says no.

I didn’t want to throw the torque off, I just put some dielectric grease inside the coil boot and put it back on.

 

Emissions, I don't call them early, iridiums are good for almost double that.

 

2016-2023 Toyota - Ignition Coil - Toyota (90919-A2008)
About $112 currently at Sparksparts.com. Wouldn't be a bad idea to order a new coil pack, to go along with them fresh plugs. Realistically, as long as you torqued it back to spec, and maybe give it a check in 50-100 miles, I'm sure the original will be just fine.

 

Thanks wouldn’t hurt to have one ready just in case.
I found one on sale at Toyota 91.53+tax shipped, about to order one