Iridium spark plugs
05-09-18, 07:51 PM
#17
Lexus Fanatic
I think the biggest argument for replacing them, isn;t the plugs themselves, but the heads they're mounted in. If you leave them in too long, you may have a plug or two sieze in there and trying to remove them may really ruin your day. Do a Google search on "Triton v10 spark plug siezed". They now make kits to repair damaged threads in those engines.
Last edited by roadfrog; 05-09-18 at 07:58 PM.
05-10-18, 10:15 AM
#18
60k plug change per Steve per Lexus.
if you go a lot longer than that he has experienced harder removals. Squeaking noises. Partial removal. Then back in. Spray wd40.
if you go a lot longer than that he has experienced harder removals. Squeaking noises. Partial removal. Then back in. Spray wd40.
05-10-18, 11:53 AM
#19
Lexus Fanatic
A lot of dealerships/mechanics will say things like that to get you to do services/get things replaced while you are there.
05-10-18, 05:58 PM
#20
My personal engine building experience is that an extended tip plugs exposed threads slowly carbon up. Removing a heavily carboned plug can damage the aluminum threads in the head, the extended use of Denso plugs may well work fine as my Honda’s Denso plugs are 105k miles change.
Quite likely Lexus has found that THEIR engine has less chance of damaging the head during removal from lower mile changes with THEIR particular plug choice.
Steve mentioned the harder removal and actually noises from high hour plug changes. Do you think he was lying just to build up his tickets?
my service guide says 60k changes. The requirement for the emission warranty may not be the ONLY reason. Says at 120k miles also which is out of the emission warranty period. They could have extended the plug change if no other reason.
the 11.8 cr is a lot. Unheard of as far as I know. Maybe the ultra low emission high compression gasohol fueled motor carbons the plug threads. Soft head?
Quite likely Lexus has found that THEIR engine has less chance of damaging the head during removal from lower mile changes with THEIR particular plug choice.
Steve mentioned the harder removal and actually noises from high hour plug changes. Do you think he was lying just to build up his tickets?
my service guide says 60k changes. The requirement for the emission warranty may not be the ONLY reason. Says at 120k miles also which is out of the emission warranty period. They could have extended the plug change if no other reason.
the 11.8 cr is a lot. Unheard of as far as I know. Maybe the ultra low emission high compression gasohol fueled motor carbons the plug threads. Soft head?
Last edited by Caflashbob; 05-10-18 at 06:12 PM.
05-10-18, 06:12 PM
#21
Lexus Fanatic
A lot of dealerships/mechanics will say things like that to get you to do services/get things replaced while you are there.
05-10-18, 06:18 PM
#22
denso, Ngk, say no. Can foul the plug.
05-10-18, 06:25 PM
#23
Lexus Fanatic
06-17-21, 08:53 AM
#24
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 OE 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've thought of this 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 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 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.
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 OE 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've thought of this 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 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 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.
The following 2 users liked this post by DrQuality:
Daswede420 (03-30-23),
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