Don't be like me. Change your spark plugs on time.

I should have guessed it would be you to give the insight. Great explanation

 

I can appreciate that math.

 

Just to add, if you're doing the math to determine the new torque value, the percent in that equation should be the percentage of remaining torque, not the percentage reduction.

So for 30% reduction, you would have 70% remaining, so the equation is: New Torque = (Torque spec) * (1 - 0.3) = (Torque spec) * 0.7

 

My pickup is on its third set of plugs.....I do them every 100k miles (I have the 2.7l 2tr-fe). I have always used a very thin line of the silver/gray antiseize on my plugs.... regardless of type. I don't use a torque wrench, I just follow the instructions on the box .....it's usually hand snug plus 1/4-1/2 a turn for most plugs.

Once long ago I had a jeep with the 4.0L straight six. The #6 plug got stuck and broke off inside the head. The only thing left in the head was literally the threads.... nothing else. I paid a guy 20 bucks to heat the hole in the head a bit with a welding torch for about 90 seconds (propane wouldn't do it).....that was just enough for the easy out to grip it and pull it out. I got really lucky that day....best 20 bucks I ever spent.

 

Thanks OP, guess i dont need to change my sparkies anytime soon

(5 years, 87k)

 

I removed a spark plug when I bought my 2012 TRD with 158,000 miles. It had a new Denso copper plug. I just changed the plugs at 191,000 miles with Denso. I found the gap in the old plugs to be more than double of factory specs. They didn’t appear to be very worn and were clean. I swear I can feel a slight improvement in performance and increase in mpg.

 

I use the nickel based anti-seez on just about everything- it has the highest temp rating. I've never experienced a factory iridium plug that didn't feel like it was going to strip the threads coming out- they've been in there forever. Yeah, they come out, but it doesn't give me a good feeling.
For the anti-seez I use, I've done the math, and the math says to lower the torque by 15% if it's only on the threads. If you're using a "bolt" and slathering it on the underside of the head, and also the threads, then it's more like a 35% reduction; most of the friction is due to the head of the fastener, and not the threads- this should make sense. I just put it on the threads and ignore the 15% reduction- you need to go to like 1.5X the spec to start to reach the yield point on a bolt (hex head cap screw)

When I was ~20 my dad had this POS '82 Buick Regal with a V6. When it was like 8 degrees out the car wouldn't start . It was the spark plugs- and it was waaaay past the change interval. We didn't have a garage. The rear two plugs on the RH side were very difficult to access. I would work for a while and then have to come inside to warm up. And repeat. All day. Man was I pissed. After that I started keeping track of maintenance on his car and did it in the warmer weather

 

It's always good to have two suppliers to guard against a single sourced failure to supply. Like if there was a fire at the NGK factory, or NGK was having major quality issues, then you'd have to rush to find an alternate supplier that could supply thousands of plugs per day- which wouldn't be possible to immediately do, because the alternate supplier was just selling a few to the auto parts stores. So yes, two suppliers, when possible, is always a good idea if they can both supply the same quality.

 

Same as my 83 Monte Carlo with the v6. Two person job to get the #6 one

 

nothing worse that having to go tighter before you can break a stubborn plug free.

it feels like a Hail Mary.

 

PICs?

 

I had to do this once. It gave that high screech sound in both directions too. Never had to resort to it again but I don't think I've ever gotten over it.

 

fack. now I bet I know what tonight's nightmare will be about.!!! hahahah...

I was on the phone with my mechanic when he told me to do it. he says he does it all the time. it was a jagged pill for sure.

 

I think I read some postings a couple of years ago that suggested not to use Iridium spark plugs in the second generation 4.0. The postings highly recommended staying with copper plugs and changing every 30,000 miles. I don’t remember why. Are there known issues with Iridium spark plugs?

 

Nice platnums or the like and no need for 30k. Best of both worlds

 

Yeah those early turbo v6 with the turbo on the rear part of the intake...
Would warm the heart of hillery Clinton

 

I changed the spark plugs on mine (Denso) and figured out from service records that they were in place for 115,000 miles. The electrodes were worn down, but except for a slightly smoother idle, engine showed no real difference in performance or gas mileage. Denso were the replacements and I'll change them at 50k which should take me to ten years.