Original Spark Plugs at 117k and 10 years

I recently purchased a 2005 DCLB 4X4 to replace my 2005 Prerunner. In the process of going through the truck, I changed the plugs. When I pulled the first driver side plug, you guessed it, NGK on the driver side and Denso on the passenger side. These were the original plugs from when it came out of the factory. It never ceases to amaze me how people just do not think to change the spark plugs these days.

I haven't had a chance to look real close at the plugs I took out yet, but the gap looked to be about .005 or even more by my "eyeball" gap gauge. I was just wanting to finish up last night - dang mosquitoes almost carried me off!

Funny thing is that the oil was recently changed, the brake fluid and power steering fluid is fresh and I am pretty sure the coolant was flushed recently. I am wondering if they took it in for a tune up and were told that the plugs were changed but the shop may just not have done them - either an honest mistake or a scam.

Anyway, If you buy used, take the time to go through it after you buy it and do all the PM to make sure you know it was done, and done right. I think it says a lot that the truck was still running decent even with 10 year old plugs that were almost 4X past their change interval.

On to the transfer case, and front and rear diffs next!

 

Let us know what else you find. Usually people leave all the diffs / tcase oil in it from the factory.. it makes me cringe.

 

How did the truck runs before you changed spark plugs?

Regarding your comment about the .005 gap. I assume you meant .005 over the std. gap which is around .042-.044?

 

I show .039 to .042 as the range, but to answer your question, it ran a little rough at idle, but, not too bad considering the shape of the plugs. I meant to say .050. Got a little Dyslexic in my typing. And I think I am being conservative in that estimate, it may be more. For kicks I was going to put the gauge on a couple of them tonight when I get home.

 

Just after I first met my wife, I changed the original spark plugs in her honda civic with 135,000 Km of city driving on it, gaps were over .060", with the ground electrodes having a knife edge on the ends. Fuel economy improved by over 25%, nevermind driveability and power. The new plugs were paid for after 1.5 tanks of fuel. Sadly, the catalytic converter had to be replaced because of the neglect. Hopefully you fair better.

 

I finally got around to putting a gap gauge on the old plugs and they ranged from .060 - .063. Just a "little" out of spec.

Changed the front and rear differential and transfer case oil and I don't think those were ever changed either. There was about 3/8" of sludge/shavings on the magnetic plugs (well on the two that have the magnetic plugs). Any way, I feel pretty good now that I have all of the routine maintenance done for now. I have two hub assemblies coming that should be here tomorrow. Won't have time to change them until Friday or Saturday.

 

I accidently left mine in my 2006 V6 for 110k and it ran fine. I don't know why I went with new Densos.

 

I'm surprised you guys had such good luck with your spark plugs, I changed mine at 30k exactly and the driver side NGK's definitely had some signs of wear and my truck has been running much better now

 

My shop foreman has 215k on the original plugs in his 07' V6. He says he's just going to wait until it starts causing an issue. He laughed at me when I told him I changed mine at 30k. He's one of the best technicians I have worked with. All highway easy driving.