This thread has woken many to the issue of spake plugs waking out. For that I'm grateful.
Still we're seeing more and more plugs fuse to coil and threads in heads burnt-out as fleet ages. Number one reason seems to be plugs walking out. At first plugs may sound like exhaust leak, sound going away after warm up. But over time, sound doesn't go away. At that point gasses are blowing out thread constantly. Spark plugs not firmly seated and ground must weaken the spark. This in-turn draws more power from coil. Coil then over heats. It's a bad cycle we can prevent.
I just swapped out plugs as a baseline for me. Mileage is 75k on an '06. The old plugs(NGK) looked great and the truck ran fine. I replaced with the Denso Iridium TT plug for the 2UZ-fe. Time will tell but the truck runs great, as it did before. I do wonder if it will help with the drone in D at a stop. I haven't driven it enough to tell if it helped or not. One thing of note is the TT plugs come with a gap of .039in./1mm, which is smaller than the Toyota gap of .043in./1.1mm. Denso says to not adjust the gap on these Iridium TT plugs so I installed them to see how it goes.
Anyway, I'm posting this here because the typical plugs of 3,4,5,6 that have been coming loose were looser in my engine than 1,2,7,8. I still needed a wrench to loosen them up, but they were noticeably looser than the outside cylinders. I'm sure they were torqued to spec by the PO. I torqued the new plugs to a mix of recommendations between Toyota and Denso. Toyota recommends 13ft/lb and Denso recommends 15-22 ft/lb. I split the difference at 17 ft/lb. 13 always seemed light to me as I've had vehicles with aluminum heads that used a spec of 25 ft/lb so I'm comfortable with 17.
Good documenting Dace.
I went back and looked a The Black Knight thread. I see plugs (NGK) were cleaned and re-torqued to 13LB-lbf at 59K miles with just a touch of anti seizes. Denso states to reduce torque by 20% if thread lubed, as those were.
So I'd say this shows 13lb is just not enough, since they loosened in only 16K miles. I've since gone with dry threads (not lubed) to 15lb-lbf on new plugs (washer not crushed) and 18ft-lbf on used plugs (washer crushed).
I've read a bunch on here about people having issues with the #7 plug removal. I didn't have any trouble with it. If you not only remove the fuel line/vacuum line bracket as
@2001LC said, but also remove the bolt that holds the A/C line to the bracket on the firewall, the bolt holding the LH rear engine cover mount and the vacuum line to the VSV(?) mounted on the IM, #7 becomes much more accessible. The A/C line only has to move a little bit to make it easier to remove the coil. Mine didn't want to come out without loosening up the A/C line. I wasn't going to force it either. The other parts removed/loosened give room to swing a wrench from the top of the motor without a swivel if you don't have one. It only take a couple extra minutes to do these extra steps and makes the job easier, IMHO. HTH.
I've not tired that, interesting!
I've just keep using my short extension and universal. Setup protrudes and 1" above spark plug tube. But using a universal is also tricky when torquing. Trick is to keep inline with plug. If it gets off at and angle, it changes torque. Also to much angle and the porcelain of spark plug may break.
This is what I use in tight areas like #7. No universal and Long extension where I have clearance.
So, I had to go back to 2003 for the kit to show up. Since the coils were the same across the years, it's all good but I wonder why not listed for the later years?
I was thinking, difference in browser. But I've gone back to Denso with google chrome and checked through the years. Found you guys are right. Some years kit just doesn't show. But I like you Dace, believe they're all them same kit 98-07 LC or LX just like Denso show the coil is.
I run into PN # issues all the time.
www.partsoug.com is my go to for OEM parts and diagrams. It's was very helpful when I was swapping engine with different models. It's seem one of the most accurate when VIN # used. If you go to partsouq and look for your vehicle without VIN #, you'll be shocked at how many models and configuration their. In fact, it's near impossible to get the exact model without VIN #.
At
Genuine Toyota Parts for 2000 Toyota Land Cruiser|Base 4.7L V8 - Gas | Toyota Parts they have very bad diagrams and PN# list. They recommend adding VIN # in order screen. Without it you'll get wrong parts.
I spent a great deal of time build parts list. Then hunting down the parts. The fastest and best for me is my local Toyota parts guy. I've used one guy for about 20 years. It cost a little more than online ordering. But it faster and he's has right part for me 99% of time. If I need to see a part, he'll order just so I can see or take to match or whatever then I can return. Relationship matter!
