Same here, hand tightened each one, just wanted to make sure they were snug... maybe 1 or 2 turns with the wrench... Didn't want it as tight as few of them were. I was worried I was going break them as a few were really, really tight. Slow and steady wins the race here...

 

This is best i can come up with. I think it read 15 for cover bolts but you can see what you read.

 

Thanks for the PDF. On page 19 of 35 I see 15 ft lbs for the seal washers and 9 ft lbs for the perimeter bolts on the cover. Also on page 4 and 5 of 35 I see 18 ft lbs for the fuel pump nuts...I was looking for this spec as well. For those interested I used the following torque specs for my job:

- Spark plugs 14 ft lbs
- Fuel pump nuts 18 ft lbs
- Valve cover seal washers 15 ft lbs
- Valve cover perimeter bolts 9 ft lbs

 

Here are a few pictures from my spark plug replacement. I also replaced all the tube seals which should take care of the small leak I had in one of the tubes. 7 out of 8 were dry.


7 out of 8 tubes were dry. I had a small amount of oil in the 2nd tube from the front on the driver side.

My old plugs with close to 100K on them. Left side is driver side and right side is passenger side and top of the picture is the front.

These are the plugs I used.

New plug.

 

"When installing the new plugs, be sure to apply a bit of anti-seize compound to the threads"

Oh my GOSH NO!!!!

NEVER.

Plug manufacturers and engine manufacturers strictly mandate NO anti-seize compounds.

Plugs have a nickel (or zinc) coating to their spark plug threads which allows them to be easily removed, even after 120,000 miles. Car makers and spark plug manufacturers NO LONGER recommend using ANY anti-seize on the threads of new spark plugs. DON’T apply anti-seize to any spark plug threads.
With compounds the torque requirements are different...

Additional issues can occur if you use anti-seize compounds.

Since anti-seize compounds contain metallic, electrically conductive ingredients, the ingredients can come in contact with the electrodes on the spark plugs, leading to misfires.

DENSO says NO.

LEXUS says NO.

NGK says NO.

Autolite says NO.

AC/Delco says NO.

Champion says NO.

Just say NO.

 

Has anyone had trouble removing the battery box? Mine is not coming out. The left screw (closer to the fender) was completely rusted and the other one was so rusted that it stripped when I started turning the wrench. I was able to get the plug out by bending the box upwards. I was just going to break it and replace it but it's still intact.

 

My recently purchased 2007 Lexus LS460 with 119k miles was, based on mileage & lack of any on‑point vehicle history, due for a spark plug change. I researched this extensively online before the work was done, and so I have accumulated all that knowledge -- much of it coming from this website, thank you all very much -- into a sort of 'single‑source primer' for other owners to readily access. Apologies in advance for any minor inaccuracies.

EXECUTIVE SUMMARY: Be aware that the market is apparently flooded with ultra-low-priced counterfeit Denso plugs, especially on Amazon & eBay, so be cautious from where you buy your plugs. Ultimately I purchased the Denso Iridium TTs at Advance Auto Parts for $9.29 each before tax. The OEM Denso Iridium Long Lifes were about $17-$20, depending upon the source. I purchased the TTs from Advance Auto Parts since Denso specifically lists them as a National Distribution Partner, something that led me to believe that the chance of getting counterfeits from Advance would be slim. The job books at 2.3 hours of labor. I paid an independent mechanic (who specializes in Toyota/Lexus product and has prior experience working as an auto mechanic in Japan) $198.00 to install them. So, parts labor & tax, I was in for about $280.00.

ALL THE DETAILS: The 2007 Lexus Warranty & Services Guide, page 53, states the vehicle should have a spark plug change first at 60000 miles, then on page 61, again at 120000 miles. Further, the Lexus Canada maintenance schedule also states the vehicle should have a spark plug change first at 60000 miles then again at 120000 miles. Changing at 60000 miles would be required in order to remain qualified for Federal & California-mandated Emissions Control Warranties. Those warranties are laws that require, under certain conditions (parts, age and/or miles), that the dealer must repair at no charge any vehicle that fails smog so that it passes. (You can look it up if you want to know the details & conditions.) However, the owner must be able to show that he/she properly maintained the vehicle according to its maintenance schedule. So what I believe Lexus is saying by requiring a 60k spark plug change … is that it is not going let itself be "put on the hook" for repairing USA cars that fail smog ... unless (among other things) the spark plugs were replaced at 60000 miles in order to maximize emissions outcomes.

Page 610 of the 2007 Lexus LS460 Owner's Manual specifies Denso OEM Long-Life (SIP-Super Igniting Plug) Iridium Spark Plugs, FK20HBR11. The Denso part number is #3473. The Toyota part number is 90919-01249 but it’s the Denso 3473 that will be found in the box. It's a V8 engine so yes it takes a quantity of eight. This is the same spark plug that is OEM even for the 2017 Lexus LS460, the last year for this V8 engine.

Around 2015, however, Denso released a next-generation-technology iridium spark plug that fits this vehicle, the Denso Iridium TT (Twin Tip) spark plug, IKBH20TT. The Denso part number is #4705. There is a Toyota part number but nevertheless my Toyota dealership told me it was not available to order; I suppose they prefer installing the higher-priced (hence higher-markup) OEM plugs. The retail cost is about 40% that of the Denso OEM Long-Life product. The major difference is that the ground electrode shape was changed from a flat, round "pancake" to a protruding tip (hence two tips) of smaller diameter … and the proximity of the two tips means that a slightly smaller gap is specified. The Denso website plainly offers the Iridium TT as an alternative installation versus the original Iridium OEM Long Life product. Denso says both have a life expectancy of over 100000 miles. Some TT users (but not many) report slightly better gas mileage. Also some users report that the TTs are more difficult to counterfeit. The Denso webpage describing the benefits of the Iridium TT product is found at https://bit.ly/3hRxdNH .

After much searching & reading, I've concluded that the OEM Long Life product appeals more to manufacturers & dealerships because it (1) is a more conservative product … that it provides some small additional degree of reliability & longevity at the expense of the improvements in ignition quality, fuel economy and engine performance/acceleration that the Iridium TT claims to provide. And because it (2) retails for more than twice as much … thereby jacking the pricing-out of dealership tune-ups significantly (even though the dealerships may actually be obtaining them at a very low wholesale cost). I am visualizing this as sort of in the same way that it seems that new cars are always equipped with lower-quality tires that don't last very long, no matter the brand of tire or brand of vehicle. Some owners just keep coming back to pay the dealership over and over again to re-purchase the same overpriced low-life "OEM" tires … when there are actually much better tires available for less money in the open market.

Again, the spark plug job books at 2.3 hours of labor. For the DIYers, there are at least three YouTube videos illustrating the work: https://bit.ly/3gBbZRY , https://bit.ly/3wAuRr4 , https://bit.ly/35u5bQO . Both of the air filter boxes have to be removed. On the passenger side, the battery and the battery box have to be pulled to gain access to the back plug. On the driver's side, if you have a magnetic swivel spark plug socket and a 4" extension, you can apparently easily access the back plug without moving/removing anything else. Or you can 10mm-unbolt and scoot‑away the Ignition Module box module to get your clearance. After you pull the ignition coil pigtails, the ignition coils are each held by a single 10mm bolt to the valve cover. Some of the ignition coils will require you to pull the spark plug tube seal out with the ignition coil to get the needed (additional one-eighth-inch) clearance to pull the ignition coil out easily; this is the procedure recommended by the Technical Manual (as opposed to levering the engine itself with a heavy pry tool). According to online videos, the tube seals are notched so that you can just pry up & out each tube seal with a flat screwdriver head after you have partially extracted the un-cleared ignition coil. Excessive oil on an old plug and/or ignition coil is a signal to replace the leaking spark plug tube seal and to monitor for possible replacement of valve cover gasket.

These Denso plugs are pre-gapped and should NOT be manually gapped, else engine damage may occur. You can certainly check the gap, though. However note that there are plenty of DIYers that say the gap in these Denso plugs are usually off. And they claim there is a special tool that can safely correctly gap precious-metal spark plugs such as these.

Also a lot of warnings from Denso and other manufacturers of iridium plugs to NOT use any anti‑seize on them when installing them. Most plugs today come with a thin coating of anti-seize that will not damage the engine, that won't cause an inability to remove the spark plug later, etc. If you were RE-installing USED spark plugs for some reason, then that is a different matter.

As long as you are replacing the spark plugs, you might as well replace all the rubber spark plug tube seals. You are "already there" anyway … and they are certainly going to have a decent chance of drying-out and/or cracking & leaking before you reach 240000 miles, especially if you are in a hot & dry climate. And they only cost about $4 each. The Toyota part number is "11193‑38020 Gasket, Spark Plug."

In case you find you need to replace an ignition coil, that Toyota part number is 90919-02250, about $50 each, but you can find aftermarket for much less if you want to go that way.

Also, "while you are there," this is a good opportunity to physically/visually check the platinum hot wire on the MAF sensor for dirt, foreign material, etc. and replace if needed.

 

Nice writeup!! Where did you end buying those authentic Denso plugs?

 

"...I purchased the Denso Iridium TTs at Advance Auto Parts..."

I got mine at Auto Zone.

 

Stop making fun of my reading comprehension!! Thanks, I did miss that.

 

I got mine from a Lexus dealer who sells on ebay...

LEXUS OEM FACTORY SPARK PLUG SET 2007-2016 LS460 LS460L 90919-01249 | eBay

I think it's a good deal and it's OEM...

 

How much closer are you to pulling the front tires off the ground using the TT's? Or ... how many more 10's of mpgs were gained? I jest slightly, but it doesn't sound unreasonable from reading the Denso propaganda to maybe see a slight gain. Of course every zig n zag spark plug makers have made to the spark gap design get's advertised as "big gains." But the TT looks legit. I'm considering these spark plugs for my LS since I'm at 56k miles. But mostly I'm considering them for my old Scamp. Anything I can do to help that car in the quarter mile, without making it look like a dragster is fun for me.

 

On the Denso website, it lists Auto Zone as its OTHER major National Retail Distribution Partner. So someone is likely good to go there as well. NAPA and O'Reilly, btw, are NOT listed.

 

It seems that posters on this forum generally agree that Bell Lexus (of Scottsdale AZ) is a reliable source of discounted OEM Lexus parts. I have already bought some items from them (wiper arm assemblies, for example). However I will say that I suspected, after shopping hard, that their "OEM" floor mats to not really be OEM. I shifted over and started sourcing OEM parts (the spark plug tube seals/gaskets, for example) from MyLParts.com ... that being Lexus of Rosedale, California. They offer a 10% discount to ClubLexus members via the promotion code "CL5."

 

My local Lexus dealership offers 15% discount for OEM LS460 parts.