The nice thing about rockauto is the fast shipping, plus their reputable you can trust that they wont sell you anything fake. Have you tried search your local parts store and or the dealer to see how much they cost.

That mixture if you can find those chemicals near you sounds like a good plan. Let us know how it works, I may try it myself.

 

Yeah let us know if it fixes the problem, remember you'd have to probably run many KM's/tanks to see if the problem comes back.

 

Well.. that was interesting.
Only got front two plugs changed. Front pax (USD Driver) has oil in cylinder on the plug. Doesn't appear to be leaking down from valve cover seals so likely is carbon/gummed up oil scraper/control ring in that cylinder. Looks like there will have to be a seafoam/PEA soak done in future if it doesn't clear up from spirited driving thanks to its new life...
So after doing top end cleaning with CRC GDI cleaner, it was an interesting job. Sprayed it through the little plastic resonator chamber thingy after the MAF and kept a rag surrounding the tube as to not impact the MAF reading (you can hear the idle change if you bypass the MAF this way).
Let it soak 1.5 hours or so. RPMs don't drop much with this stuff compared to the 4cyl videos I saw but I'll be damned if we didn't poop our pants when revving it at the end to clear some of the deposits out, valves made the 'clack' sound twice. Nasty sound.

Anyway.. the results you ask? (keeping in mind I'm very pessimistic of 'mechanic in a can')


drumroll...








After doing the treatment, CRC GDI Cleaner has saved the day. Keep in mind this car has NEVER thrown a code until today when putting a slightly still damp (post clean) MAF sensor back in too early. We thought bluedriver/torque wasn't reading the codes which made us nervous.. now we know.

It's like a new car. It has no hesitation, bogging, stumbling, shuffling gears around, sluggishness, random pulling of timing depending on the position of venus, and it hauls *** (and this is before cleaning MAF!). Boy does it haul ***. Timing doesn't go below 0 much/if at all and is almost always positive now. Fuel trims/etc still monitoring and will report back after plugs are done (with photos of all of them) and we can drive it for a while. Economy is shooting up too even thought it got thrashed last night.

Floored it on an empty motorway and was expecting to see 80-90~mph max.. nope.. she was knocking on 120mph, the beast went off the clock! (180kmh speedo). It's never pulled so hard and so smooth, but it's nice to know it has no speed limiter like most JDM cars (literal Jap import still in mystery rune user interface..). It even lit the rears up in 1st (has sort of done this but very rarely as it's usually super temperamental in 1st/mashing throttle at low rpm) and spun them flashing the TC light all the way up to 55-60mph through 2nd. It has NEVER EVER done that before in the dry (well ever, period), I couldn't believe it.

Mrs is stoked, happiest (car related happiest ) I've seen her this year. Changed everything as we were dreading having to pull heads and do guides/major mechanical stuff with big downtimes and potentially higher costs. One day will gladly pull heads/motor apart and give it a refresh at 200k miles+ now we know it's worth the effort but we need to see how this fix goes through a few tanks first before definitively celebrating (maybe a traditional kiwi rear-roasting party when tyres are due..).

So after reading an identical problem/post by another user https://www.clublexus.com/forums/gs-...l#post10275657 who did everything and much more than we have done (except tensioner) I PM'd them to check the tensioner out. Our behaviour/issue was exactly the same for anyone else reading this post or theirs. Oil wicking cylinder issue is described in theory in post #2 - might be interesting for someone else having same issue, could be gummed up rings that need hard driving OR soaking with PEA to remove carbon.
Will be doing oil in a week or two when mrs has some spare shekels for it just in case hard carbon issues are present, might be an opportunity to do the cylinder ring soak to remove carbon before changing. GDI emulsifies the carbon unlike other non-PEA products (Seafoam I'm looking at you) so shouldn't damage anything - valves, CRC saw no cylinder scoring in all their test vehicles (also no blocked cats - cat smell has gone all of a sudden...) but oil contamination particularly would be of worry for me over longer term use without changing. May get it oil tested as well.

So to do: rest of plugs, clean TB, new air filter, keep an eye on oil permeating in front cylinder to see if it clears or not before more drastic measures, tranny flush, diff fluid, make some new rubber/fabric shock strut covers (rubber has perished). Cabin filters, find the volume **** or get a replacement one. Treat the suspension parts with sillicone spray (using WD40 bulk at the moment but it doesn't last so long). Rotate the wheels (the rears are probably going to be killed prematurely at this rate with how fast this thing is now haha) and pull the ABS module/booster to paint under it (muppet mechanics didn't tighten the brake lines and it leaked from prior owner.. killed some of the paint/rust issue sgoing into winter).
Wishlist also includes a certain TCU upgrade, maaaaybe try swapping ECU to get it running less rich under peak load (yeah they gimped the GS by running afr in the 9s to pull 20-30hp lower than the LS..), the electric boot mod would be cool and the rear rubber cover for the boot needs replacing.
LCD screen needs the conductive pen trick, or it'll get the tesla replacement. I do prefer the original look though.
English conversion will also be something we want to dig into eventually, warning messages in Jap get pretty frustrating, even though the seatbelt chime disable procedure is in English!? Weird.

I think we bought this car just in time from its' old owner and their horrible, shade tree-yet charge the earth mechanics' practices. Looks like they went all through the electrical system trying to figure these issues out as there are no codes and it does seem trans/electrical related. It appears that some of the loom has been replaced - maybe they did the trans loom already thinking trans was the issue (trans was horrible until tensioner was replaced and still not perfect until now).
But due to all this (and some monkeys not tightening the ABS module after replacement?) It was an absolute steal due to the issues - 4,500USD with ~80k miles. Paint pretty good aside from some small damage on the rear.

One question - Wiper relay: anyone know where this is? I literally have the electrical workshop diagram manual and it's NOT on there. Want to get rain sensing wipers working for winter coming fast. It works manually triggering them but does not auto-sense/run intermittantly. Only continuously.

But lastly thanks to all of you amazing contributors and members here. We have scoured countless threads trying to resolve this issue and now it appears to be simple - tensioner + top end clean made most of our issues disappear. Please do not migrate this forum to facebook, which is the death of car forums, I hate that place. Will look forward to contributing further here as we dig through the car and do more work on it.


So thanks again to you all and happy lexus'ing

 

Hahahah Thats awesome! Im glad to hear shes running good. Because you live in austalia, the air has more particulars sand etc. So its more prone for you vs a car that see clean air. You might want to remove and clean or replace the pcv valve aswell as its easy to do.

 

Quick update - still very, very occasionally pulling timing (not near as much) on steeper hills under moderate load at low rpm (under 1300) around 70-80kmh. Longer than it should take if changing gears. Still not near as much power loss though but not all plugs are changed and that would make sense (one has no top electrode tip), also TB cleaning still needed. So economy still hasn't gone all the way back to where we expected yet.
Still responds instantly and pulls hard if you mash the gas (which it usually wouldn't prior) and timing is fine at higher rpm.
Short term fuel trims don't go under 4% during this. Long terms can go from 0 to -10%. Left bank slightly more trim than right but seen many other cars like this.

edit: we are in NZ, close enough. Air is pretty clean here but more salt spray than anything else this time of year.
PCV is a good idea too I need to learn more about where/how and will add it to the list. Thanks @ibidu1 !
p.s. do you know where the washer relay is? I've checked all main fuse boxes, both in compartment, one in the boot IIRC and the main ones in the bay..

 

Sorry I do not know where the relay is located

 

Hey mate, fellow Kiwi here.

My 460 has the exact same symptoms you are describing here, and Lexus HB won't even touch it, Toyota NZ say its trans pressure, but I spoke to a transmission specialist who says it's definately engine related and suggested cleaning the MAF sensor, which has already been done.

Plugs are good, just did those recently.

I have an endoscope on the way to see if I can take a look at the intake valves before I pull it all apart and clean them by hand, which I really don't want to do.

Do you think that CRC product is worth a shot?

Is your fix holding up?

Would really appreciate it if you could flick me a message, 212442327.

I have a video of how flat it is which I can send, and see if the symptoms are relatable.

My tensioner is fine also.

Cheers mate.

 

@ibidu1 No worries. Going to dig in LS460 area.

TB was much worse than since last inspection and got a full clean out, rest of plugs done too. One of those green dish scrubbers that's plastic and some alcohol did wonders.
All plugs have varying levels of cover leak except cyl 1, which was ever so slightly brown coloured on top of electrode but was the only plug without any visible recent valve cover leak.. it was pulled during the cool down period after applying top end cleaner. This is the only thing really concerning me at this point - it leads me to consider if it's just cleaner, or related to carbon gummed oil rings, or it's the first few pots to get the heavier crank case vapour (anyone run catch cans?). Oil consumption is okay but it gets a topup ~1-1.5 qt before each change which seems pretty normal judging by other owners feedback but could be a bit better. No smoke only carbon on first heavy accel after a while.

Plugs are arranged as lower left is #1 and top left is #2 (except for 2nd photo which is #5 as lower left)
As you can see below #1 plug has that very faint oil browning while being the only one without a glaringly obvious (current) valve cover/plug tube seal leak..


#5 lower left


#1 lower left


Few days after doing plugs/clean out/etc, performance has returned (and stayed) and improved further (as well as feel) via TB and rest of plugs. Massive noticeable difference to drive-ability, low end response and economy is climbing back up and she goes fast without having to drop down a gear which is great. Partial throttle response is like a dream.
GDI cleaner must have also lubed up the TB to help it work better hence giving a 'false positive'. Before cleaning, rubbing alcohol wouldn't pass through the TB, after cleaning it leaks through. No more timing pulling, it's always positive except two brief exceptions: -1 to -1.5 during rapid off-throttle transient twice in about 50 miles of driving. Long term fuel trims are also halved and the ecu is still re-learning so I get a feeling it's solved now after multiple re-starts cold/hot and a few days. Will take it out for a blat tonight.
Top end cleaner definitely helped but I think another chunk of this was plugs. One plug was loose as hell and it turned out to be caked in burnt oil (the worst plug #3). So compression in that cylinder must have been abysmal... my old XV10 camry wagon had a similar issue and fixing that plug made it be able to go up hills in 5th gear again..

Also been wondering if giving it a tank of e85 might help with top end cleanliness too. Will be doing an oil treatment, then a change, plus pull/clean plugs, inspect, replace tube seals to see if we can get things clean and all running white without oil contamination.
I wonder if using cheaper oil briefly (start, warm a little, light rev then off) would damage the car? Just to flush anything out as much as possible without using expensive oil wastefully.


So far 2-3 days out and fix has held up after doing rest of plugs, TB and MAF.
Do you have whatsapp/signal/etc instead? I don't live in an area with cell reception so almost never have credit so not much use. When mrs is back with the car I can get her to text you though as her place does have cellphone reception.

Have you checked tensioner by hand after de-tensioning the belt? Checked water/alt/other pullies etc? Tensioner can cause noise that the knock sensors hear without you being able to hear it or being particularly bad. It's cheap so could be worth replacing, worst comes to worst you have a spare. Changing it stopped (temporarily) our issues for a few weeks until the added power made more issues.. If there is any play in the bearing it's junk. Also check the plastic guides between the tensioner arm and the mounting base for it. Ours was cracked and about half missing as some ******* mech had done a bodge job to get it 'repaired' for the prior owner.
CRC made a massive difference without having to change/do anything but it only lasted a day until plugs/MAF/TB was properly cleaned. It will at least give you an idea if your issue is related. Although CRC says it doesn't other people have reported hard carbon particulates in oil so I would change it after a week or two of cleanign the rest out. Some said it required two cleans... we can't afford 2 oil changes so quick so will use an oil cleaner first to take as much of the gunk/deposits out and it may help with scraper/control ring cabon issues on our engines. MAF cleaning gained no sensitivity back (airflow at idle was same but idle sliiightly lower) but may have helped, we are talking fractions of a percent or maybe in partial throttle response. I think CRC lubed up the TB which really helped the most and it definitely removed some carbon from plugs before even proper heat cycling (pulled 2 plugs while it was heat soaking before road use part of the CRC cleaning instructions). BUT we also had a clean TB upon first inspection without removal and it has only as of late got really bad. In fact, you can't see all the TB gunk from the outside without removing it, most is behind the blade.. you have to remove it to inspect it properly if you have no already tried I would recommend that to be 100% sure.

Do you have bluedriver/torque/techstream?
If so, monitor the timing advance vs abs load, long term and short term fuel trims, even your economy meter will give you the best idea, it will tell you if the engine is happy. You'll see the tacho jerk, shifts will be clunky (especially when downshifting if you floor it) and the car will not pull as hard as it should. We also thought it was TCU related at first as it drives like **** and trans is rough as guts when the engine is unhappy. But, after this now, we have done NOTHING to the tranny, flush/fluid change is up next. Not even touched the tranny harness/plug. So we had similar poor gearbox behaviour but in the end it was all related to engine as when that's pulling timing it just doesn't respond/rev/do what the trans needs as quick as it should, thus there is a disconnect. The trans tables don't seem to learn for a literally timing retarded engine. Now the trans is perfect without doing a thing.. I think this issue is caused by a range of problems (we thought we'd nailed it with tensioner first time) and the engine will pull power at the slightest hint of trouble.

I think you're in Hawkes Bay? If you're up in AKL any time soon you're welcome to come by and we can see what your car is doing on bluedriver. Always nice to meet a fellow lexus enthusiast. Also happy to double check anything you might have missed. I would definitely pull the TB and inspect fully if not done yet. Endoscope may not help as you really have to measure valve with a gauge like this http://carspecmn.com/ls460-and-ls600...g-andor-p2119/ if it is guide-related.
That said you may be able to see if it's burning hot, useful tool I've also been thinking about getting one.

Also keep in mind we have had zero codes this entire time until putting wet MAF back in too quick and leaving an ignition coil unplugged.

​​​​​​​Good luck!

 

Thanks for the reply mate.
2-3 days is a good start, if I coult go that long without this issue I'd be so happy.

Not really on those apps mate, but I can look into them. For now, this will have to do. Even if you get her to flick me a text, I can send my name and you can add me on messenger or something.

Yeah I did the water pump like a month ago, so that's brand new, checked all the other pulleys while I was in there and they are all perfect. Also did the screwdriver to ear test and no audible vibrations from the front at all. Everything's perfects up front.

I'll probably pick up a couple of cans of CRC and give it a whirl, can't hurt for a cheap attempt. Probably pair it with tgmo injector cleaner also, as in my time at a Toyota stealership that D4 cleaner proved its worth time and time again on all sorts of vehicles.

It's definately something to do with AFR or air flow and metering because its obviously rich;
I can smell the cat getting hot when I lean on it.

I haven't had the TB off yet actually, so that's a good point of call. I'll take a look at that at the same time. Cleaned the MAF twice with no gain, had another laying around to try, also no gain.

No OBD2 equipment unfortunately. I have had it on GTS at the stealership and they claim thier logs show nothing, but who's to say, they won't show me the results or take me for the tests. Be good to get my own, is the bluedriver worth it? I've heard mixed things.

Taupo but I do pass through Auckland a lot, Pukekohe then up to Whangarei, so it might pay to stop by sometime when it suits.

I think my goal with the endo is to see if I can get an eye on what the carbon situation is like on the valves and ports. I've seen it before on direct injected engines where they foul to the point that they actually produce knock and or airflow issues just from carbon alone. If that's the situation then I'll pull the manifold, but I don't want to go down that road unless I have to, got a bad back.

I'm not too worried about valve guides, I doubt that will be my issue. I guess if it comes to that I'll just scrap it and get a later one.

I also haven't had codes at all, except when I ran it without the AFM to see if it would default to a base map. (It didn't)

Edit: What engine oil are you running? I had a side thought that the vvtie could be having issues with some engine oils.
​​​​​​​
Cheers mate.
​​​​​
​​​​​​

 

When you finally seem to nail this problem the driving feel and relief is priceless... such great cars!
Was your pump leaking? What kms? I think ours is as we have to top water up a little time to time and it didn't used to need that a few months ago. Will be checking it next weekend or two when we do valve cover spark tube gaskets.

You shouldn't need more than one can of CRC to test this. Just follow the instructions exactly. You will not hear the rpms drop much on our engines, especially the first few shots as it has to soak/reach it, it's not a poxy four banger that nearly chokes from it. Also keep in mind to have centre of spray applicator in the middle or outer edge spraying to middle of intake tube to avoid pooling and get as much as possible down the gullet. Have someone sit in it to set 2k rpm, appraently it's like driving in traffic (the amount of effort to keep around 2k). CRC also recommend ~1000 miles before cleaning further as it does clean over a week or two of use (dyno confirmed..). It emulsifies the carbon instead of make it flake off in big chunks so as long as you do oil it shouldn't damage parts/block cats etc, had a good email chain with the national product manager about this

We also noticed cat smell is significantly reduced/mostly gone after fixing the issue - by not pulling timing the engine is burning fuel properly (well more so - the GS runs a little richer than the LS in order to reduce power rating a little..). Mrs didn't notice cat smell at all today. It would still smell in past under moderate-medium heavy accel (not just flooring it) if it hadn't been cleared out for a while. It does appear after slow driving for a while then flooring it (e.g. clearing a few days carbon/crap out). But has reduced significantly since fixing it, when pulling timing it's acrid and you smell it after 3-4 runs till it clears, it takes forever to clear out and will come back during a spiritited drive sometimes.
That said the cat smell is a known issue on many toyota engines from ours to four bangers, it's the pre-cats that out-gas a little sulphur, fuel quality can also change this. But when it's really noticeable and acrid it's pulling timing definitely.
One good test for you - if your car is sluggish under 2-3k rpm, go up a long, steep hill and hold the throttle. Most cars will accelerate till you reach load/fuel/etc and just sit there, our cars when pulling timing will add timing back in as rpm increases (in our case) so you are making more power at the top of the hill and it continues to accelerate up the hill if you hold same throttle position. If yours does that then definitely it is pulling timing. You'll also see it doing 2-3km/L on the instant fuel gauge when it's sluggish and the usual tacho notchy behavior, smell from cats on the onramp etc.

Injector cleaner did give us a brief increase in economy but this was before this latest lot of fix attempts, worth a shot every 10-20k km. Tried nulon for that and I think STP, both performed similar.
Will give it another shot once plugs/oil is done or just prior.
Oil cleaner for rings will be last 'liquid mechanic' fix.

You are aware our engines have port and direct injection? I don't think carbon buildup is as bad as the IS but it's definitely worth keeping an eye on or inspecting but I'd first try CRC, 30 bucks vs 150 bucks for an endo + time. Plugs should tell you most of what you need though, if they are bad then the rest is bad. I could visually see a difference (check the #1 and #2 plugs in prior post vs first post..), the larger deposits of carbon are reduced quite a bit, valves will get the spray directly so would be even better. And those plugs in last post didn't even really get a heat cycle to clean like the others.
I'm happy to pull the manifold with/for you if you're up this way (will work for beer/endo loans etc ) if it does get to that but I think you'll have same issue as us.

I was a superbike and honda car guy in a past life (now the s2k has an LS3 lol) so fully understand where you are coming from re: oil. We are using Penrite enviro 0W-20. After 4500km it's still very yellow and in good condition. That said the car has only just started making reliable good power so that might change as it gets more heat cycles from my past experience running full-synth engines.

Bluedriver was not listed as specifically compatible for our cars (and was cheapest) but at that point we had nothing to lose. Just make sure it's a later version of bluedriver hardware there are a few, we got one off trademe from this seller https://www.trademe.co.nz/motors/car...a8f79bb2cb-001 they're 5~20 bucks incl shipping and to be honest have been invaluable for monitoring/testing these fix attempts. Edit: you'll need a copy of 'torque' from the app store to interface with it as the 'reader' on your phone. You just need to add a few gauges to measure the timing/trims/absolute load/rpm/maf etc. So far it's actually done okay and picked up deliberate/obvious faults correctly. Techstream is probably better (TIS) but it's more expensive usually (50-80NZD).
Welcome to come up and try it out up here. I think you won't need to once you clean that TB though, I think their GTS (fancy reader I assume) won't see anything sitting in the shop either as the car isn't throwing any codes, it's not misfiring or bad enough to do so. We had to drive (particularly steep hills with partial throttle) to really see anything coming up after GDI cleaner with timing advance..

P.s. if it's sluggish, if you back off the gas fully then mash it on again does it pull hard? We noticed this as a 'trick' to get it to behave if you needed full power.
P.p.s if you do give up and scrap it let me know I'd definitely be keen to grab some parts especially if it's a black interior but I think you'll figure it out!

Should have a text now

Cheers mate have a great evening and good luck!

 

How often are you replacing the oil in the car? Personally im kind of old school and replace it at 2500-3k miles. On my 350 Im at 190k and hardly any oil burn, never had an oil light come. The 460 and 350 have the same pistons and rings. Guys with 350's have had oil consumption issues, many who have these issues run their oil 5k-up. My theory is that over time the oil collects sand/grime/carbon etc and this gums up the pistons oil control rings.

More likely that white ash is the cleaner that you used. Although they do look oilly

When I do throttle body cleaning I simply remove the throttle body by 4 bolts. I spray it completely inside and out, and open the butterfly to get to the inside nooks and crannies. I will spray the inside of the intake manifold itself with a carb cleaner

 

8000km or so for oil which is about 5k miles. Car is not used in anger much so it's a reasonable distance but perhaps can try the lower change intervals. As oil ages it does thin out and will get past rings easier if it's going to happen.. Shall have to give it a try, I think you are on to something. 0w-20 is already super thin as far as oil goes which exacerbates this issue. This time we will be changing at 2.5k miles and it's used about a quart or so, no surprise after seeing the plugs.
Intake manifold does need a clean out, it has secondary throttle butterflies as well which must be difficult to get to but are far less of an impact to engine response due to less precision or partial use needed for their operation.

Ash-like coat was present before cleaning and is on most plugs I've seen posted here from other users. It's hard little ***** under magnification, I can post one if you want to see. A clean 460 without oil leaks seems to have white electrodes usually. At first seeing them I thought it was coolant or something and was surprised at all the soot, not used to DI. Reminds me of leaded gas in planes a little, with the white deposits.
The slightly more reddish colour of plug #1 now after closely inspecting one photo, is definitely from the cleaner. False alarm. So PCV/seals/oil cleaner and earlier changes and lets see what happens to consumption, hopefully have nipped it in the bud in time.

Edit: Also have a plug seal failure theory. If you look at these plugs, the front ones have least by far amount of leakage if any. So heat-related would be my guess. We might try run with covers off and see if it reduces heat soak, and run them back to back on vs off IAT + coolant as well.

Cheers

 

I would def replace the valve cover seals, if not both sides atleast the side that is leaking on to that spark plug. They do not look too difficult to replace, and should easily come off. While youre at it you can remove the pcv clean and test it to make sure it works, or replace it.

Before your oil change you can top off the oil with about half a quart or a bit more of atf transmission fluid in the oil and run it for about 1000km of easy driving. The detergents will help clean the internals, if you think your internals are gummed up. I use regular castrol gtx oil, 5w-30 with an oem filter. There are better oils that I should be using, but since this is a daily driver, and I replace my oil often its cost effective. Plus it doesnt see high rev nor a lot of heat for me to justify putting synthetic.

 

S2kiwi hasn't updated for a bit so I will:

ibidu1, valve cover seals are on their way at the moment so will be done in the next week or so. I think it will be an easy job all considered and at a lower cost than expected so looking forward to getting it done. Curious to hear if there's any updates on your situation.

Since the big clean-up and spark plug change our issues are nil. Car runs beautifully, predictably and has the power we wanted. Strange to be driving it and not waiting for it's next hiccup. We still get a little cat smell sometimes, but only if it hasn't had a good run for a while. It's used for commuting and often sits in traffic so every week or two we try to make sure it has a good outing. Smell disappears fast and smells a lot less than it used to. No timing issues etc. Poor car just needed a bit of upkeep, clearly the previous owners' mechanics were not doing their job. We know he tried to sort issues but it appears he was being well and truly had.

We're also doing air filter/cabin air filter/ the trunk release latch and tyres over the next week or two, then saving for the next round. Fluids, water pump, brakes are on the list. I am pretty confident by years' end we'll be up to date on everything and it should be preventative maintenance from there.

 

Hey there! I have a 2016 lexus nx200t f sport. My car has about 127,000 miles. In the last 6 months I’ve gotten a new battery, brakes, oil change, fuel pump, spark plugs and coils. I recently got a check engine light about a week ago that says low engine power and traction control off and the two codes are p219c and p0301. I took the car to a mechanic and he initially said it was a fuel injector. He replaced the injector but the codes are still there. He told me he thinks it’s the valve guides. I’m not sure what to do at this point do you have any advice