The 4Runner has started and run fine every since I bought it 35k miles ago. I finally got off my lazy butt and decided to change the plugs. I went for the easy kill first and pulled the left-front plug. Much to my dismay, the plug felt cross-threaded and was difficult to turn until the last few threads. It also squeaked like a 20 year-old, rusty lugnut being removed. Not good. I was somewhat relieved to see rust and not buggered-up threads.



The rest of the plugs were equally difficult to remove. Luckily, on reinstall some anti-seize on the new plugs and I was able to hand-tighten them most of the way. I would advise anyone who doesn't know the history of their plugs (how long they've been in there) to remove at least one and check for corrosion.

The plug changing process was relatively straightforward. One of the connectors on the coil packs was a bit tricky to remove. I used a mini-awl with a curved point to get in behind the clip:



Another tip: when removing the plugs, with the last few threads still holding the plug, remove the socket and hold a shop vac nozzle up to the plug cavity to suck out any debris that might fall into the combustion chamber upon plug removal. I also hit it again with the shop vac right before I insert the new plug.

 

How many total miles were on your rig?

 

I have a story to share as well.

My very first Toyota was a 2WD 1979 truck with the 20R engine.

On a Sunday long long ago, the day before I was to report to Boeing for my very first day of work, I decided to tune the rig up.

Did all the other stuff first, and saved the plugs for last.
It was apparent that whoever did the job before had not used any anti-seize compound.

I broke a plug off to my dismay.
My brother came over with an easy-out, and I could not get it out.
I had to drive the rig on 3 cylinders to a shop a few miles away, and dropped it off there.
It would be ready by Tuesday they said.

This was in the afternoon, then we had to drive clear over by SeaTac airport to a car rental place and secure me a vehicle for a few days.

It all worked out, I got to my first day on the job just fine that Monday, and I had my '79 back by Tuesday after work.

Moral of the story, always use that stuff when doing plugs.

 

About 115k. Who knows how long the plugs had been in there...

Yeah Corey, I thought I was going to be in for a day of grief. The resistance didn't feel like the plug was gonna snap, just that the threads were hosed. I had visions of me trying to retap the plug hole down in that deep well and knowing that metal shavings would end up in the combustion chamber no matter what I did. Pulling the heads - didn't even want to think about it.

Hopefully, my apathetic attitude about the plugs will help motivate others into action and to use anti-seize as well.

 

I have always used a little engine oil on the threads of my plugs before install, and have never had a problem. But I do live in Colorado and it is very dry here. I would not install plugs without using something on the threads.

 

i'm a chronic with spark plugs (and every other part of maintenance). i just did mine a few weeks ago, and before that i did it last november. unfortunately i only started documenting all my maintenance at the start of this year when i found the mpg.xls sheet that someone uploaded here on yotatech. i added a maintenance section to it and my new year's resolution was to get more organized, so it's a start.

 

that sucks ive always used anti-seize

 

Is it worth it at ~62K miles to replace the plugs on my rig with the denso iridiums? Maybe some plug wires too?

 

lol i think soo i would stick with denso or ngk dual ground plug and for the wires i got ngks there cheaper from www.sparkplugs.com

 

but with the mileage I've got, it does seem worth it?

and yeah, I'll use antisieze

 

thats why some of these aluminum head motors spit spark plugs out (metal fatique). looks like you caught it in time! that is why i don't like the maintenance schedule put out by alot of manufactures. i would never leave plugs in for a 100,000 miles (intridium, paltinum or not). at 100,000 miles you are likely to pull the threads out with the plugs.