LS460 engine response

[TyrannosauRoss Lex]

Hi,

I haven't done a huge amount of "pedal to the floor" driving recently but I did today and put the car into manual mode and 2nd gear, the revs were at around 3000rpm and I put my foot down and it felt like about 2/3 the power.....so it was brisk but not that quick, after about 1 second I took my foot off for a couple of seconds and then put my foot down again and it took off, from similar rpm, much, much faster. This seemed to happen a few times.

Any reasons as to why this may be? The car is going in for a service within a few weeks so I'll mention it then but just wondering if anyone knew what the cause may be? I'll be needing to use the car tomorrow and may give it a bit of stick to clear the cobwebs a bit.

Thanks in advance!

[ambermarine]

The best way to check out the engine performance against ecu criteria is on a rolling road with read out analysis takes all the guesswork out.

Although Lexus dealerships do not have that facility their software is pretty good and they should be able to find out what is what.

[TyrannosauRoss Lex]

Thanks for your reply. I drove it earlier and think it might be the gearbox, perhaps.... I put it in manual mode again and I could still feel the gearbox changing gear at times, which is a little odd to say the least. 

It should be going for a service within 1-2 weeks all being well. I will get them to check the oil level, top up or even change if necessary, and see if they can reset the gearbox software. 

[TyrannosauRoss Lex]

OK so after a bit more driving and a bit more spirited driving it seems a little better. I have been doing lots of long-ish trips sat at 50mph lately due to M27 roadworks and haven't really stretched its legs for a few months, so maybe it just needs a good thrashing? It seemed noticeably better earlier, I will monitor it more over the coming week or so until it goes in for a service.

Any other thoughts/suggestions are most welcome!

[royoftherovers]

4 minutes ago, TyrannosauRoss Lex said:

OK so after a bit more driving and a bit more spirited driving it seems a little better. I have been doing lots of long-ish trips sat at 50mph lately due to M27 roadworks and haven't really stretched its legs for a few months, so maybe it just needs a good thrashing? It seemed noticeably better earlier, I will monitor it more over the coming week or so until it goes in for a service.

Any other thoughts/suggestions are most welcome!

An LS 460 and a good thrashing are to my view a contradiction in terms Ross.

[TyrannosauRoss Lex]

Maybe so, but one should have full power available if one wishes. Having a 4.6L V8 is, for most times, a complete overindulgence. It's nice to know it's there in case you need it though.... 

[steve2006]

Don’t the newer models learn driving styles and adapt to that, perhaps with you just taking it steady the ECU wasn’t ready to react to a sudden change but is now relearning hence the improvement noticed.

[TyrannosauRoss Lex]

This is exactly what I was thinking, and was wondering if there's a way to reset it some how. On my old BMW 7 series there was, something like have ignition on but engine off, depress the throttle all the way down past the resistance so kickdown would be engaged, and then hold for a while, ignition off whilst still holding pedal.... Something like that but can't remember exactly. 

Will see how it is next time I drive it. It's the first time the last 2 days I've really floored it for a few months.... It certainly does pick up and go for an old bus! 

As an aside.... What are the "ECT" buttons PWR and SNOW? I'm assuming they're either throttle or gearbox maps? What does ECT stand for? 

Thanks! 

[ColinBarber]

1 hour ago, TyrannosauRoss Lex said:

As an aside.... What are the "ECT" buttons PWR and SNOW? I'm assuming they're either throttle or gearbox maps? What does ECT stand for? 

Electronic Control Transmission. Yes essentially they are throttle/gearbox/traction control maps.

[ambermarine]

The learning capability as been a feature of the LS400 from day one I was shown this feature and actually practised it by my tech at Lexus back in 96.

This is why the thrashing on the motorway or in sports mode improves performance the ect power is basically there to prevent the gearbox changing up when accelerating and overtaking manoeuvre's are taking place causing a drop in forward speed which could be fatal.

The snow mode does the opposite so as to prevent wheel spin .

[TyrannosauRoss Lex]

The issue I have had is that the ability to floor it on the motorway from time to time has been non existant. Unfortunately my grandfather passed away 4 weeks ago and I've been driving to see my nan most days. It's a 20 mile trip, 16 miles motorway, and the whole motorway section is 50mph average speed cameras (M27) so it's just basically been a case of taking it easy to warm up, by the time it's warm it's sat pootling in 8th gear at 50mph, then there isn't any way to stretch its legs once off the motorway. The past 2 days I took a couple of detours though. I'll see what it's like next time I drive it though. Is there a way to reset it some how? Aside, I assume, disconnecting the Battery (which I'd rather not do). 

[ambermarine]

The reset can only be done with the ECU software and that is through The dealer ship be careful of using any other software programmes or systems such as snap- on as they have been known to corrupt the initial factory programming and mess up the engine running correctly.

With regard to normal operation the  engine and gearbox Ecu's will learn the new driving modes and change them as the driver or driving changes ,not overnight it is subtle   but it does happen.

[Cotswold Pete]

Just reading this post and wondering if its worth getting on the blower to Japex and seeing what they think.  Not sure if this is Osaka territory, but no harm in calling them as well.

Give them a shout if the local service dealer cannot pinpoint anything specific

[PCM]

10 minutes ago, Cotswold Pete said:

Just reading this post and wondering if its worth getting on the blower to Japex and seeing what they think.  Not sure if this is Osaka territory, but no harm in calling them as well.

Give them a shout if the local service dealer cannot pinpoint anything specific

+1 Japex - excellent.

[TyrannosauRoss Lex]

They are quite far away from me though! There is a well reputed Jap indy not far from me I think so if needs be I'll contact them. I need to use the car on Thursday so I'll see what's it's like then and report back!

[TyrannosauRoss Lex]

Just an update after I took the car out earlier, once it had warmed up I left the gearbox in automatic mode but set to PWR, put my footdown to engage kickdown and once the gearbox had shifted down 2-3 gears it took off as it should, I didn't notice any sluggishness to the engine. I tried a few times and every time it seemed absolutely spot on. 

Fingers crossed it purely was just the fact that I hadn't given it anything more than about 1/4 throttle for 2-3 months!

These LS460s do get under your skin, don't they. They're very good barges with a fairly decent turn of pace.

[rich1068]

As others have mentioned, it has to be the ECU/gearbox adapting to particular styles. If it's sorted now then fair enough and I agree that disconnecting the Battery isn't ideal but on my GS there are two fuses that can be removed to force the reset without faffing with the Battery or losing all other settings. Possibly something similar or the LS460?

[TyrannosauRoss Lex]

Good to know, but hopefully I won't need it!

[rich1068]

Agreed. Just keep ragging the nuts off it 

[Malc]

2 hours ago, TyrannosauRoss Lex said:

They're very good barges with a fairly decent turn of pace.

likewise my old and ancient ( now 230k miles )  Ls400 I drive in permanent  pwr  mode  I think it actually improves mpg AND it's permanently in "  go  go  "  mode, raring to go and just flies along when the throttle gets floored, there's never any hesitation,............... apart from the passenger though 

Malc

[TyrannosauRoss Lex]

OK so a bit of an update.....I think there is a problem, but God only knows what it is.

The car did the same again the other day before having a full service, under full throttle (engaging kickdown) it was revving cleanly but genuinely felt like about 50% power. If I backed off the throttle and then reapplied.....100% power. It went in for full service and I mentioned the issues. When I drove the car to the garage it felt absolutely fine. They plugged it into diagnositcs....absolutely no faults with anything, nothing logged at all. Checked the emissions, checked the cat, checked the plugs etc etc....nothing. Absolutely fine. They ran injector cleaner through it just to check that wasn't an issue.

I was driving home last night from somewhere and decided to give it the beans and again, sometimes it takes off like a scalded cat and other times it was just seemingly underpowered. It's just hit and miss and I've no idea why!!!!??? The trouble is, if nothing is logging on the ECU and nothing can be found....what the hell could it be? Half of me thinks it's a sensor or software related, but short of disconnecting the Battery for 30mins and then risk not being able to get the car started I'm not sure what to do...and that's not something I fancy doing, and risking the fact I may not be able to get the car to work again.

It's very odd, the car has been incredibly reliable so far and I still don't think it'll let me down, but this just seems really weird! Any thoughts?

[Tulpen]

On 5/31/2020 at 8:00 PM, royoftherovers said:

An LS 460 and a good thrashing are to my view a contradiction in terms Ross.

I reckon this is the best observation you've had. In 23 years of LS ownership (400 & 460) I've never needed to floor the pedal. Your car is 14 years old and, even though it's an LS, isn't quite as sprightly as it once was. I find, on the odd occasion, that I can still show a clean pair of wheels at the lights, to any Golf GTI owner who wants to show an old codger what power looks like. And I can do that by just flexing my right ankle a little bit - nowhere near 'kickdown'.

But, hey, it's your car.......  🙂

[TyrannosauRoss Lex]

13 minutes ago, Tulpen said:

I reckon this is the best observation you've had. In 23 years of LS ownership (400 & 460) I've never needed to floor the pedal. Your car is 14 years old and, even though it's an LS, isn't quite as sprightly as it once was. I find, on the odd occasion, that I can still show a clean pair of wheels at the lights, to any Golf GTI owner who wants to show an old codger what power looks like. And I can do that by just flexing my right ankle a little bit - nowhere near 'kickdown'.

But, hey, it's your car.......  🙂

The issue as well that the car has been slow to respond or dimwitted at low rpm. For example, there is a hill near me that is 1 mile long and averages 7% gradient. There was a time when I'm having to use an awful lot of throttle just to get up it, which is not typical for this car. To effectively say "you shouldn't floor the throttle" kind of misses the point. The engine should behave the same each time, and that isn't happening. I just took it for a drive and it didn't feel right, after 3-4 miles I stopped and tried doing what my old BMW 7 series "gearbox adaptation reset" was....which was ignition on and engage kickdown and hold for 30 seconds, then turn the car off. Once turned back on, the car drove 100% fine, although I'm not convinced it was the throttle with the ignition on that sorted it of couse.

A little before it went in for its service was the worst time, at low engine speed (eg 1200rpm) and about 1/3-1/2 throttle the reps would hunt up/down for a short while. Applying a lot more throttle it would then rev cleanly but with much lower than normal power. a few minutes, if that, later....it was driving absolutely fine. It seems very sporadic.

It is a very strange one, especially because nothing was logged in the ECU as fault codes. I am pleased that the cat was OK though, as that would be a pricey fix!

[Tulpen]

17 hours ago, TyrannosauRoss Lex said:

The issue as well that the car has been slow to respond or dimwitted at low rpm. For example, there is a hill near me that is 1 mile long and averages 7% gradient. There was a time when I'm having to use an awful lot of throttle just to get up it, which is not typical for this car. To effectively say "you shouldn't floor the throttle" kind of misses the point. The engine should behave the same each time, and that isn't happening. I just took it for a drive and it didn't feel right, after 3-4 miles I stopped and tried doing what my old BMW 7 series "gearbox adaptation reset" was....which was ignition on and engage kickdown and hold for 30 seconds, then turn the car off. Once turned back on, the car drove 100% fine, although I'm not convinced it was the throttle with the ignition on that sorted it of couse.

A little before it went in for its service was the worst time, at low engine speed (eg 1200rpm) and about 1/3-1/2 throttle the reps would hunt up/down for a short while. Applying a lot more throttle it would then rev cleanly but with much lower than normal power. a few minutes, if that, later....it was driving absolutely fine. It seems very sporadic.

It is a very strange one, especially because nothing was logged in the ECU as fault codes. I am pleased that the cat was OK though, as that would be a pricey fix!

That's a lot more info.......so you're having trouble at low RPM as well as on kickdown. It sounds to me as if it is time to take the car to a Lexus specialist, with all the right diagnostic kit. There are guys on here who can give you the names of the best people around in the UK. 

What sort of fuel are you using? Our cars (2006/2007 LS460) are on a list of Lexus models that need to use Super Unleaded (as was) or E5 (as is). I've always used the recommended fuel and had no problems.

How many miles has your car done? The 430 and 460 suffer from a problem where, after time, engine coolant can get into the auto box via the oil cooler.  Most of us have had a new radiator fitted - I had mine done last year at 12 years/100,000 miles.

I hope you get this fixed. There is nothing worse than an intermittent problem.  

[TyrannosauRoss Lex]

The car is now on 102k miles. I don't believe it has had a replacement radiator. What are the symptoms and signs of coolant going into the autobox? It has had a recent inspection so they should have picked that up if that was happening, no? The gearbox is still smooth, if coolant was getting into it, would it not be a bit more jerky, and perhaps the problem would be more consistent, and would the gearbox not misbehave? It changes gear fine.....?

I am based near Fareham/Portsmouth in the UK if anyone knows anyone? I use normal unleaded fuel, not premium