New spark plugs, yes or no?

[Redefined]

Martin. I changed mine at about 75k. In my opinion they didn't need doing and subsequently I found a vid by Scotty Kilmer explaining how these newer iridium tipped plugs that don't need re-gapping can go 150k without a problem... Possibly alot more!

On my H6 i would try to change em (myself as it was a flat 6 engine and hard to get to the tighest plugs, meaning many mechanics didnthave a clue and would leave them out) at about 60k. But after reading/watching Scotty Kilmer (and also that Car Care Nut doesn't include it in his list of things to keep your car running nice) explaining how we're OCD with our plugs on newer cars, I'd say not to worry about it.

If you really want to check em out, they're easy enough to get to. So save the £250 and maybe just pop one out - I think in my V8 thread I talk through how I did my change and it was straightforward - and take it from there!?

Am sure you'll make the best decision and a good question indeed to ask... Scotty vid below (but bearing in mind, he's esssentially a YouTuber now so does need 'content' and an opportunity to talk lots to gain them extra watched-time minutes).

[Malc1]

Wow …… are you quite sure these iridium plugs can satisfactorily last for 150k miles ? 
Malc 

[Brian R]

On 9/11/2023 at 1:39 PM, johnatg said:

It is ridiculous to change plugs on an age basis - they only need changing on a mileage basis at, at least 60K miles and they will usually reasonably last to 100K miles or more - see Car Care Nut on YouTube for an informed person's take on this.

On 9/11/2023 at 2:38 PM, Barry14UK said:

Are you sure you will still get Lexus 'Relax' warranty if Plugs not changed at specified time/mileage?  Lexus Cheltenham told me I couldn't pick and choose items to leave out.  Consequently, due to age, my plugs were changed at just over 40k miles, much too early! 

22 hours ago, ColinBarber said:

There is no time schedule on plugs only mileage, as per the vehicle's service schedule. Relax requires you to service according to the schedule, so you are perfectly fine not to change them before 60k miles. Owners here have confirmed this with Lexus HQ in the past because dealers keep stating these lies.

But in this particular case, if the plugs have never been changed after 16 years, I'd at least remove and inspect them - if for nothing else other than to ensure they aren't seized to the engine.

Couldn't agree more with the above, and here is my take on the self same recent conundrum.

On the subject of Relax and whether one has to adhere to the service schedule verbatim, I can advise from my experience it is not necessary and the warranty stands if you had a minor instead of a major but see below....

Earlier this year I took mine in for what should have been its third MAJOR service at just, 12000 miles! The service manager agreed it was nonsense to apply a 60k major service, which on this occasion would have involved spark plug changes. Common sense would clearly show plugs that had only done 12000 miles do not need changing. I was advised the Relax warranty would nonetheless remain in place.

This time based servicing can and does make a mockery of the whole idea, and I've certainly had other cars that were rightly based on mileage, albeit with an intermediate oil change if deemed advisable. Taking mine as an example, it has had 6 oil changes in 12K miles, all manner of filters changed etc, etc when in reality much of what was ripped out had hardly seen any service whatsoever!

So unless our spark plugs have some metallic/porcelain/iridium degradation over time, I, for one, will continue to suggest mine are not changed until the car hits 60 thousand miles. Mind you, on present mileage that could be 24 years hence. If I still have the car 😂 then, I'll park it outside the pearly gates and sell it off cheap on the implicit understanding the plugs might be hard to remove. Mind you, the "climatists" will no doubt stick their oar in long before that!                   

[ColinBarber]

1 hour ago, Malc1 said:

Wow …… are you quite sure these iridium plugs can satisfactorily last for 150k miles ? 
Malc 

Not all miles are the same - 10 miles on the motorway is clearly different than 10 miles stuck in traffic for hours. Ideally they should be changed on the engine run time or number of sparks but there isn't a mechanism to  keep track of that.

Until recently in the US the recommended change interval was 100k to 120k miles, whereas the same vehicle/engine in Europe had a 60k schedule. More recently the US schedule has been more aligned with Europe, but clearly the plugs can go 120k+ miles.

Unless you are doing high mileage I'd stick with the 60k schedule though, and you need to if you are keeping up Relax warranty - I don't see this as a big issue, you will probably only ever have to change them once during your ownership of a vehicle.

[Redefined]

1 hour ago, Malc1 said:

Wow …… are you quite sure these iridium plugs can satisfactorily last for 150k miles ? 
Malc 

 

There you go Malc. I'd been changing the iridium plugs at 60k or less on all my Subarus and mever really noticed any change or wear on the plugs (though I tried to justify and sell it to myself). Car Care Nut appears to agree with Scotty Kilmer and I definitely value CCN alot more for our cars.

 

Other servicing is alot more vital... Really good thorough vid...

[Redefined]

 

 

@Malc1 this guy is just golden. So informed and straightforward and some of what he mentions is the reason I started building my own (push) bikes (for customers eventually). That then LED me to be more confident working on my own cars.

At the rnd of this vid he mentions who he follows in YT. Automotive Express will be one I sub to soon (though I may just delete the YT app again for the mo as I found myself wasting so much time and only downloaded it just now to try and find the content of Ahmed talking about spark plugs.

If anyone loves auto engineering and Toyota/Lexus in particular then this interview is priceless (sprry for saying twice).

[T man 545645]

My car was looked after by edgware road lexus until i started using Japex Automotive about 4 years ago.

The main dealer changed the spark plugs based on a certain number of years even though the mileage at the time was really low. I've had them changed again at Japex last year as the car started misfiring (now on 135k!)

[MartinH]

Quite a variety of opinions here! My take is that if the plugs are worn-out, there is likely to be a perceptible degradation of performance and (more easily assessed) fuel consumption. Both seem as good as they've ever been at present.

[Malc1]

yep ..  might as well go on another 50k miles at least and by then you might have sold the car to some other person to worry about the then inevitable " failure "

Malc

[MartinH]

I'd never seen the Car Care Nut. I like that he inspired Shafiq to build his own bikes, a diverting and pleasing hobby with a tangible output. So much work now is just doing stuff on a computer, with no tangible output but for your fee or salary.

[Redefined]

Not quite @MartinH I started building bikes after my local bike shop allowing me to apprentice there part time (his dyslexia and our friendship, meant my bikes were always put on the back of the pile so eventuallygetting frustrated I asked to work with/for him and he allowed it). Then after so many years of slowly becoming more and more frustrated with the local 'fitters' I eventually started working on my own cars.

 

Sadly, honest expert advice/opinion online is scarce - there's lots of opinions and advice but generally the experts keep that info to themselves and why shouldn't they. After about 5 or 8 years of maintaining my own cars from a servicing and sometimes bearings POV, for Toyota there wasn't much info in YT. Dueing Covid Car Care Nut started his YT sharing his expert knowledge with the world and since then Ive gone from 'thinking I know' to 'knowing' IMHO.

Malc, I don't think him (Care Care Nut) or Scotty Kilmer are saying to leave the problem to the next owner and nor do I have thay philosophy. I personally like to sell my items in a condition that's the same or better than how I bought em. For example, the wife has bought the 22 year old Honda Civic as her first car. She doesn't plan on keeping it too long (lots of reasons that fly about in her brain) but I'll be sorting out as much rust as poss, have already ordered the auto gearbox fluid and oil/filter (filter being an original Toyota).

I've also figured out why the headlight isn't breathing properly and has condensation in it so that shall be sorted v soon too. Regards the auto fluid, generally the capacity is much larger volume than how much can be flushed and replaced at a time. During my guesswork days - and most people on the forums or YT would condone or suggest this - I'd do a flush, drive it and then another flush or two. Trying to get as much old gearbox fluid out of the box as poss.

Since Car Care Nut has come to YT (he's a Toyota Master Technician and learnt his trade startting at a tender age of about 7!!) I've since learnt that the flush is vital in allowing the gearbox to run smoother. If you purge out all the old fluid then the tiny particles that help 'plug' worn areas cannot do their job and can lead to failure...

Spending the extra £250 on the plugs certainly wouldn't do much harm, but what Scotty Kilmer and Car Care Nut as suggesting is to spend the time and effort in servicing other vital areas. Like for example (and I learnt this from CCN also) the coolant flush is vital to be done regularly and on time (or more often). It stops worn/dirty coolant from circulating around the engine and seals.

Also, he (Car Care Nut) suggests that the 8k miles or longer oil/filter change is too long. He advises to change the oil at least every 5k miles (which is what I now do on the Lexus but was also doing in the Subaru 6 cylinders before this) and its a better investment of your money. Hope that helps 😊

[Malc1]

1 hour ago, Malc1 said:

yep ..  might as well go on another 50k miles at least and by then you might have sold the car to some other person to worry about the then inevitable " failure "

Malc

you might have felt i was being a little sarcastic  well guess what ....  I was ..........  it's a poor show not to do the plug change at 100k miles when they've never been changed 

just my view ............. leave it to the next owner to worry about and save yourself that £250 eh !

Malc

 

[Redefined]

@Malc1 I didn't mean to offend... Just my opinion based on what I've seen when getting em out and what those two said (Scotty and CCN). But, I come from a slightly different mode of thinking as I try to just get it righy. Between spending too much (not because I'm tight fisted but because I seldom have spare cash at all) and getting the job right to last a long long time.

Not just for myself but also the next owner. Hence one of the reasons I spend alot of effort on the LS430 😉

[Redefined]

Just to add... Anyone thinking of going yhe distance on spark plugs. They must be iridium and they only one's I would trust are the NGK. For some reason I'm not 100% about Denso.

Also, coming back to Denso and NGK. There are alot of knock offs in various stores and that's why when you buy NGK (AFAIR) there is a way of confirming that they're original items made by NGK.

Also, if it's gonna play on your head whether it's the right thing to do (putting it off for another 50k) then you'd be better off just getting em done. Not worth the stress on the head thinking about if you made the right decision 😊

[steve2006]

Yes definitely make sure you are buying the genuine items, iridium is a very rare metal and apparently very hard to attach to other metals. There have been cases of the “iridium” tips falling off fake plugs with the obvious dire consequences.

[johnatg]

52 minutes ago, Redefined said:

Just to add... Anyone thinking of going yhe distance on spark plugs. They must be Iridium and they only one's I would trust are the NGK. For some reason I'm not 100% about Denso.
 

Denso is a member of the Toyota group - Toyota actually own about 25% of Denso.

Just saying!

[Malc1]

3 minutes ago, johnatg said:

Toyota actually own about 25% of Denso.

maybe a captive market then for those 8.69 million vehicles a year needing plugs ................. they won't miss the odd car here or there not changing them then !

Malc

[MartinH]

Well I feel I am miscast here as that guy who neglects his car, leaving known problems to the next owner. During my ownership it has always been serviced by the main dealer, who saved it from near-certain death in 2020 when the fuel system and electronics failed. Even after a big, and I do mean big, discount to list price on the required parts, the bill to me mounted to most of the likely resale cost of the car. After that rebuild, the car ran beautifully, and has continued to do so since. So I have no plans to sell it on, not least because nothing much in the current Lexus range appeals to me. The arguments about what to replace the IS250 with are well-rehearsed in another thread! 

[Malc1]

3 minutes ago, MartinH said:

During my ownership it has always been serviced by the main dealer, who saved it from near-certain death in 2020 when the fuel system and electronics failed.

WOW that's something to be proud of then for sure   Well done ✌️ .............  and nothing done to the plugs and that part of the system as a part of the " cure " ?  nor a recommendation about the plugs at that time from the Main Dealer's engineers working on your car  ?

Malc

[MartinH]

Not that I recall

[Redefined]

Thanks @johnatg doesn't stop me feeling that for some reason NGK are to spark plugs, what YKK is to zippers. Didn't know Denso is Toyota though. Makes sense why I always see it plastered everywhere (Denso) in various cars and other bits.

 

@MartinH I don't think anyone thinks you're a neglecter at all. Besides, we're all in together 😆

Maybe your car is someone else's next one 😊 and well done having so much of it 'rebuilt' at the MDs. Must've cost a bit 🤗

[MartinH]

1 minute ago, Redefined said:

Maybe your car is someone else's next one 😊 and well done having so much of it 'rebuilt' at the MDs. Must've cost a bit 🤗

Yes, something north of £4K! It occupied a berth on the Lexus Edgware Road service floor for about three months in 2020 (at the height of the pandemic). The problem had to be referred to Lexus GB, and in turn to the Lexus tech bods in Japan. The problem was extensively discussed, with long advisories arriving overnight (by fax of course) from Japan. These had to be translated and, frequently, sent back to Japan for clarification. I think Sunil and his team were quite pleased to see the back of the green IS250, but full marks for bottoming the problem!

[Redefined]

Well done them. Always a real boost when you/your mechs get to yhe root of a problem. Hope it keeps going well Martin.