2015 Taco spark plug confusion???

The reason not to anti-sieze is two-fold. One because of torque. Two because it can interrupt the ground path, plus anti-sieze is often just a term used and there are many products that fit that description that can worsen the ground path more or less.

 

That’s why i use anti seize specifically made for spark plugs (see photo I posted above) and make sure to apply it away from the tip.

I bet half the guys saying you don’t need it also don’t use a torque wrench, and I bet 90% of those guys don’t get their torque wrench calibrated every year like you’re supposed to. And I bet a lot of you don’t store your torque wrench at the lowest setting like you’re supposed to.

Moral of the story is, there is a lot of room for error everywhere. It’s up to the operator to make the best decision with the information available.

 

Please cite the source of this claim. I don't claim to know the reason, but a more logical reason is that Toyota is part owner of both Denso and NGK, so they put 3 one side and 3 on the other. Although this doesn't explain why this hasn't been done other V6 an V8 Toyota/Lexus engines.

 

Seeing the aviation photo on your signature I totally understand where you're coming from with your information. I will say you are correct that most individuals do not calibrate their torque wrenches, either initial or at certain intervals. In the Air Force it is determined by the PMEL AFI (precision measurement equipment laboratory) regulations for frequency and allowable variation in precision (i.e. +/- x% of the targeted value). Also the majority of people don't cycle the torque wrench 5x at the value it will be used at prior to use. Nor do people take into account the amount of torque loss through the extension used. In the Air Force we have to get our torque devices calibrated every 6 wks to every 6 mo, depending on what the regs say. I get why you are saying what you are saying because I live that life everyday. haha

Personally I have been a professional mechanic for close to 20 years both automotive and Air Force Hydraulics. I have rarely used anti-sieze and I don't know the last time I used a torque wrench on a spark plug even though I own 5 torque wrenches, 2 of which are snap on digital 3/8 and 1/2 which I absolutely love!!! I agree with your statement on anti-sieze and how to apply it. BUT most people are talking about saving $10 so you know they don't have a quality torque wrench, let alone has it ever been calibrated. lol

Hopefully people read our info and take the advice for what it is worth and make the best educated decision for them.

 

My 3.4L came that way also.

 

I'm VERY curious if anyone comes up with a link or legitimate info on the reasoning. I'm sure it is something like @Chuy said. Or maybe its some behind the scenes top secret long term experiment. haha

 

To answer your HG question, in November of 2005 Toyota changed the design of the head gasket to fix the week spot in the area between cylinders 4 and 6. Engine manufactured after 11/05 good. Before 11/05 bad.

 

So I was trying to dig up a little info on the different plugs per bank as OEM but didn't come up with much. I asked Toyota Parts Department Manager that has been a very large dealer for 20 years and is equally as nerdy as we are. Still nothing. BUUUUT I did find some interesting info from NGK and Denso's Websites.....

This is from Denso. You can see an illustration between the difference in how the flame front is created. As you can see flame front is much larger, IE creating a faster and more efficient burn.



This is also from their site comparing their Iridium Power and Iridium TT (Twin Tip). The ignition source is more focused and much stronger. Thus more efficient burn and stronger flame front than even a standard Iridium plug.



Then I was at NGK's site. This compares Nickel (what everyone refers to as Copper), A standard Iridium and their new Ruthenium plugs. You can clearly see in high speed photos the differences int the flame front. The more Red, the "hotter" the flame front. This is important so ALL the fuel is burnt. You want that to increase energy from your fuel AND it helps reduce carbon build up because carbon build up is unburnt fuel, plain and simple.



Now... After doing some stupid amounts of reading trying to find the answer to why NGK and Denso is on the same engine from OEM I found a lot of information. From what I have read from many sources, including 3rd party sources. There is no reason not to use an Iridium Spark Plug unless you simply want to save a BigMac McDolads meals worth of food. The only reason you wouldn't use Iridium is engines that are proven not to run well on them. Old cars (pre mid 80's for the most part), many early 2000's Fords were particular about the plug used and others that use "non-resistor" plugs (pre-1960's-ish). IMHO I will always recommend using Iridium if possible. I will always recommend NGK and Denso. Tank from this what you will.

 

If you apply the torque specified in the service manual but with anti seize, you can overtorque and strip the threads. Either reduce the torque to ~60% book value, or use an angle-based method like I do (e.g. half turn past rundown).

3rd gen spark plugs are known to loosen from the factory. This from a company that spends $1 million/hr 24/7 on powertrain development. Take that for what you will.

 

The Toyota P/N comes pre-gapped, so it saves a few minutes (and less chance to damage the plug if you're hamfisted with the gapper tool).

Spark plug electrodes erode a microscopic amount with each spark. At 30k, the plug gap would have widened from .040" new to about .055"-.060". If you leave the plugs in for longer, the gap will keep on widening. Larger gap is harder on the ignition coil ($$) and can cause occasional misfires. That's why Toyota can deny the warranty on catalytic converters if you haven't changed the plugs at the book interval.

Iridium plugs erode slower than copper plugs so you don't have to change them as often. That's why the TRD supercharger kit included iridium plugs, as plug access gets tighter with the supercharger on top of the engine.

I used Denso Iridium Long Life plugs in my 2nd gen with no issues. I used Denso Iridium TT plugs in my Subaru with no issues. I chose iridium because I'm lazy and don't want to deal with it every 30k. I use NGK copper plugs in my lawn mower because dirty combustion puts a lot of carbon on the plugs, so they need to be changed yearly anyway.

 

I just did mine using these, they were all gapped correct. Bought on Amazon.

$7 Toyota Genuine Spark Plug

https://smile.amazon.com/gp/product/B004T1PLDW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

I don't store my torque wrench at the lowest setting..


..but then again I use a split beam .

 

I posted what I believe to be the reason for 2 different brands of plugs in post #9 of the following thread - Sept. 2019

https://www.tacomaworld.com/threads/2014-4-0l-spark-plug-question.627604/#post-21466565

 

Ehhh whatever warranty logic and business deals that resulted in 3+3 factory config happened 18 years ago starting with the 4th gen 4Runner.

By the time the 5th gen 4Runner came around, the dual-VVTi 1GR-FE specifies Denso SK16HR11 iridiums only, for the past decade: http://s3.amazonaws.com/toyota.site.p01/toyota/manuals/OM35A28U/OM35A28U.pdf

There's also a lower 76 ft-lb lugnut torque value for aluminum wheels, which is interesting. So what torque do you use if you put 4Runner wheels on your Tacoma?

 

This is true on the supercharger install for sure! Not to mention I believe they are 1 heat range colder as well. After installing a handful or three of TRD superchargers when I worked at a dealer the clearance is very tight. On top of that, no customer wants to worry about spark plug changes every 10k miles.

On my 99 GTP with a few mods I was going through copper plugs (recommended by a performance shop at the time) about every 5k-10k miles. When I started installing TRD S/C's at work I noticed they were running Iridium plugs (this back in 2006/2007 or so). So I cross referenced my plug number that was one step cooler, threw in some Densos (since they were cheap at my cost) and would't you know......They lasted 35k+ till I traded the car in, less knock, better fuel economy and it felt better under load. Which makes sense if you look at the flame front of my post above. That is when I became a solid believer of Iridiums. Also at that time the funky Bosch +4 was all the rave. I tried those and the car would barely even run. Absolute JUNK! lol

 

This has not been my experience.

I've changed my plugs every 30k miles since I bought my '07 new over 13 years ago. The first batch that came out was the typical 3 x Denso + 3 x NGK. Unlike most on here that seem to favor the Densos, I've stuck with the NGK plugs (p/n 7787 V-Power).

I just changed my plugs again today @ 150k miles (so the plugs that came out had ~30k miles on them). The plugs that came out looked like this:



They all looked reasonable, and the gaps were still reasonable as well:

1: 0.044"
2: 0.045"
3: 0.044"
4: 0.043"
5: 0.044"
6: 0.046"

Original gaps were 0.040" when installed; all of them came out of the box gapped that way. I'd hazard a guess that if your gaps are opening up as much as you are suggesting after only 30k miles, you may have something else going on. It could be use related as well - I'm not hard on my truck by any stretch of the imagination, and the engine is completely stock. My truck is mostly used for my commute to/from work.

The only thing that concerned me a little this time was that plug #6 was not tight when I went to remove it - it wasn't exactly loose, but it took pretty much no effort with a ratchet to start unscrewing it. It is the plug on the left in this pic:



It is also the one with the largest gap, and the ground strap was substantially lighter than the others. I have a feeling that may have happened due to my torque wrench clicking before it should have when tightening it down the last go-around.

After doing a lot of reading on here and elsewhere, I decided to change my approach this time. I've always used anti-seize on all of my plugs in the past, but as you can tell from the pics above, I put it on a bit too heavy. Due to that, I decided to chase all of the threads in the heads with one of these to clean them up:

M14 x 1.25 limited access thread chaser -

$14 ARES 70692 – M14 x 1.25 Limited Access Spark Plug Thread Chaser Tool – Low Profile Design for Confined Areas – 5/8" Hex Head with 3/8" Square Drive Design for Superior Versatility

https://www.amazon.com/gp/product/B077MMG9CL/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

It was very easy to use, and worked very well. I was able to thread it in and out of the spark plug holes by hand by taping it to one of my 3/8" extensions. It removed a bit of gunk out of each hole, which appears to have been old anti-seize. Once that was gone, I decided to forego the anti-seize this time as per NGK's recommendation - all of the new plugs threaded in by hand very easily. I'm all about trying something new when it makes sense, so we'll see how they come out at 180k. FWIW, I've always had good luck with anti-seize on spark plugs, but I know I used to glob it on way too thick in the past. This is about as clean of a slate as I could muster for a good A-B comparison. It's gonna be a couple of years before I pull these back out, but I'll do my best to remember to provide an update.

I also decided to forego the use of a torque wrench this time around. The plugs in my other vehicles use conical seats, which I usually tighten by feel. These use sealing washers, so you can get them pretty snug by hand before the washer starts crushing. At that point, you can go about 1/4 of a turn more to crush the washers, but it has always been a bit unnerving to me since it kinda feels like you are stripping the threads in that process. With the old anti-seize gunk, I'm guessing that plug #6 had just barely started to crush the washer before my torque wrench told me it was good enough. After many years of wrenching, I'm starting to find some things that you just have to tighten by feel instead of with a torque wrench (e.g. brake caliper banjo bolts and bleeder screws) - there are just too many variables, especially since none of my torque wrenches have ever been recalibrated after I bought them (although I do store them at their lowest setting, minus my one split-beam).

One last thing...I'm not sure if it was this thread, but in one of the many spark plug threads on here, someone mentioned this particular spark plug socket:

$10 GEARWRENCH 3/8" Drive 6 Pt. 5/8" x 6" Magnetic Swivel Spark Plug Socket - 80546

https://www.amazon.com/gp/product/B0014ZVSVK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

It looked nice, so I bought one to add to my collection. I ended up liking it much better than my other spark plug sockets that use a rubber sleeve to hold the plugs - I'd highly recommend it if anyone is looking to add an additional tool to their collection.

 

Odd. When I changed the plugs in my 2nd gen at 31,000 miles, the RH bank plugs (Densos) all measured 0.055". The LH bank plugs (NGKs) all measured 0.061". NGK's tech info says the erosion rate is typically 0.00063-0.00126"/1,000 miles, which works out to 0.019"-0.038" over 30,000 miles. https://ngksparkplugs.com/en/resources/read-spark-plug

 

Can you provide legit source that says Toyota is part owner of NGK?

 

I couldn’t find anything other than common share holders.

Here is the biggest connection:
The Master Trust Bank of Japan, Ltd., (for Toyota Motor Corporation)
There are also other common shareholders in the links above.

https://www.ngkntk.co.jp/english/ir/stocks_bonds/shareholders_composition.html

https://global.toyota/en/ir/stock/outline/

All my research says, NGK is separate company.
NGK shares the same major stockholders as Denso.
Whether that means anything, I don’t know?

Toyota Motor Company holds roughly 24% stock ownership in Denso.
Toyota Industries owns close to 9%.
Total ownership with ties to Toyota is at least 1/3.

Again, if one has the time, they could probably trace Stock Ownership between the two.

 

I appreciate you posting the spark plug socket. I was meaning to look this up and forgot. Mine which is the right diameter is too short(or too long?) and the rubber does not grab the plugs so i have to pull them out with needle nose extended pliers which is annoying. Magnetic is even better.

I naturally reach for the antiseize myself ever since owning a 2007 F150 5.4 and the nightmare they had with the breaking plugs. Ford recommended ample application of antiseize on both the threads and below on the sleeve just before the tip to prevent carbon buildup which could make if difficult to impossible to remove the plugs. That and add the two piece design with a flaw originally and plugs from the first few years loved to break off in the motor. I only had one break off and require a plug extractor so I consider myself luckier than some. I will try no antiseize next change as there will surely be a little left over in the threads.

One thing that was interesting about my recent plug change is that the passenger side were much tighter than the drivers side. Not sure if that was a product of less clearance for the guy to man up on it on the drivers side or what.