LS460 engine response

[TyrannosauRoss Lex]

So I had to drive 21 miles to a family member's house..... I took the road up the same hill it didn't like very much yesterday (it reaches it after 1km so still cold engine). Today.... Absolutely, 100% fine. I have found there is a local Lexus independent (Lex Tech) near me. Half of me is tempted to call them and get it in, the other half says wait until (if) it happens again. I think I'm leaning more towards calling them and getting it in. 

I'm not convinced their diagnostic equipment would be better. The garage it went to use a top of the range Snap On system.... 

It's certainly bizarre isn't it! 

 

I have to drive from Eastleigh to London to Portsmouth later so it'll certainly get a bit of a run, so we'll see how it behaves. 

[royoftherovers]

1 minute ago, TyrannosauRoss Lex said:

So I had to drive 21 miles to a family member's house..... I took the road up the same hill it didn't like very much yesterday (it reaches it after 1km so still cold engine). Today.... Absolutely, 100% fine. I have found there is a local Lexus independent (Lex Tech) near me. Half of me is tempted to call them and get it in, the other half says wait until (if) it happens again. I think I'm leaning more towards calling them and getting it in. 

I'm not convinced their diagnostic equipment would be better. The garage it went to use a top of the range Snap On system.... 

It's certainly bizarre isn't it! 

 

I have to drive from Eastleigh to London to Portsmouth later so it'll certainly get a bit of a run, so we'll see how it behaves. 

Lex Tek, has received good reports from Members on this Forum Ross.

[TyrannosauRoss Lex]

Good to know, thanks! I will call them tomorrow. It seems they do collection and drop-off which is absolutely ideal.

[TyrannosauRoss Lex]

As an aside, I'm fairly sure this is air conditioning water but is this normal? Patch of what appears to be water on the left side of the car about 2ft behind the wheel. There does appear to be some sort of drain hole directly above it so I'm guessing it's normal? Haven't noticed a loss of coolant or oil. This photo was taken about 2 hours after. Parking up. It was not that warm here but humid, AC set to 18 degrees. 

Thanks. 

[Tulpen]

3 hours ago, TyrannosauRoss Lex said:

As an aside, I'm fairly sure this is air conditioning water but is this normal? Patch of what appears to be water on the left side of the car about 2ft behind the wheel. There does appear to be some sort of drain hole directly above it so I'm guessing it's normal? Haven't noticed a loss of coolant or oil. This photo was taken about 2 hours after. Parking up. It was not that warm here but humid, AC set to 18 degrees. 

Thanks. 

Yes, I think that's water from the airco system. I have mine selected permanently and that little puddle is a common sight. If in doubt, try a smell and/or lick test.

[TyrannosauRoss Lex]

Thanks for the clarification, I thought it was. 

Well, just driven from Eastleigh to London, about 90mins driving.... Car 100% fine. So strange. Maybe it was an iffy batch of fuel or something (just filled up last night), although I would have expected that to impact it all of the time. I think it's worth calling Lex Tech, explaining the situation and see what they reckon, but I'm not sure. About an hour and I have to do another 80 miles or so. 

[Cotswold Pete]

18 hours ago, TyrannosauRoss Lex said:

Car 100% fine. So strange. Maybe it was an iffy batch of fuel or something 

Good point given the rainfall we have had always a chance a little water crept into some tanks, though they should be watertight.

Does not take much water in fuel to create a problem, so fingers crossed all tickety-boo from now on.

[Peter67]

From the description the issue is quite possibly in the VVTI system. It’s unlikely to be on the inlet side as they are electrically actuated more likely exhaust size which is oil actuated. There are 2 main elements to this on each bank - the oil control valve and the exhaust camshaft phaser / adjuster and either can cause problems. It Intermittently affects the engine timing and power and does not necessarily throw up any engine codes. Power delivery can be much reduced despite engine revving cleanly especially under load going uphill. The oil control valve and the VVT phaser on Toyota engines is known to have issues with sticking operation. The Oil control valves x 2 are very simple to remove and test for resistance and apply 12v to see if they move smoothly and replace if necessary. They are not expensive. The exhaust cam phaser is a bit more involved. It is likely to be one bank of the engine that is affected but I guess you need to figure out which one. It’s possible to either use a garage level scan tool that displays the position of the 4 x camshafts to see if they are in phase or which one is out. Alternatively the output from the cam sensors can be mapped on something like a Pico scope and again you can see if you have an issue. If you have Techstream you can set the vehicle software in diagnostic mode to be more sensitive and to throw an engine code on 1 trip event logic.This might reveal a pending code for you and identify which bank you have an issue with. Good luck - these issues are very hard to pin down.

Peter

[TyrannosauRoss Lex]

That's a brilliant bit of information, thanks for posting! At the moment the car seems to be driving fine. If it happens again I'll call the local Lexus specialist! Thank you so much. 

[scythe]

Hi Ross, your 460 doesn't have an adaptive gearbox.   Earlier ones did - my 400 and my 430 both had them.  I didn't like it because the gearbox didn't always behave in the same way - if I'd been on a long journey the car drove  differently when I started the next day compared to if I'd just been driving locally.  The 460 gearbox doesn't adapt, and, especially as it has enough power to do whatever you want, I think it's a better arrangement.   The ECT thing, as people have said, changes how your gearbox responds.  I always leave mine in the PWR postion, because this means that the gearbox always drops into the right gear at the right time.  People who say that the 460 has too many gears have, I think been using the the car with the switch in the centre position. In PWR it's always there in the right gear for you.  Incidentally, I used to drive along the same stretch of motorway fairly often, and measured fuel consumption with the cruise control set, and in this situation there was no reduction in mpg over my set distance of 40  or so miles.

The lack of power thing, I had that.  After a few bits of nonsense, a (Lexus) mechanic suggested that it needed it's throttle body cleaning.  He did that, and it cleared the problem.

: o )

[TyrannosauRoss Lex]

OK thanks, if it plays up again I will get the throttle bodies cleaned. Thanks very much for the info!

[TyrannosauRoss Lex]

Hi guys,

So it happened again yesterday, and I managed to catch it on video! 

So you can see that it revs cleanly, but it's well down on power. I only noticed because under 1/2 throttle there was noticeably less power than normal, but obviously this wouldn't show up on a video. You can tell when I put my foot down as the gearbox shifts down. Later on (another drive) it started off weak again but as I got near home the car was back to 100% normal again.

Any further ideas? I will contact my usual garage and send them the video and see if they're willing to clean the throttle bodies and look at the VVT stuff, but if not, then I guess I'll give Lex Tech a call!

Thanks very much once again.

[Peter67]

It’s the same symptom as I had. Revs cleanly with no power. Then sometime later its back to normal. I assume you have no codes or pending codes?

Looks like VVT issue to me. As the VVT system is complex you will need to get it clearly diagnosed before throwing money at it. Basically you have an electric actuator (Phaser) on each intake cam (VVTie) and an oil controlled actuator on each exhaust cam (VVTi). The exhaust actuators are controlled by an oil control valve on each bank and there is a small VVT oil filter inside the cylinder head cover for each valve. Each cam has a VVT position sensor reporting to the ECU so 4 of them total. There is also 1 camshaft position sensor which is located on Bank 2 intake cam. Techstream software can connect to the VVT components and test them individually for operation.

Depending on the diagnosis the simplest issue is to replace the oil control valves, these are standard Toyota solenoid valves that slot into the rocker cover exterior on each bank and replacement takes only a few minutes. To access the VVT oil filter screens you need to remove the rocker covers (relieve fuel pressure, remove high pressure fuel pumps, remove rocker covers) then the filters are in a small housing on the inside of the cover. This also gives you access to the camshaft actuators as well and its possible to replace the exhaust cam actuator In situ without removing the main timing chain. Again genuine Lexus parts are not that expensive if you buy from suppliers such as amayama.com. Its possible to buy certain parts second hand.

Regards

[TyrannosauRoss Lex]

Thanks Peter. If it is the same problem that you had, may I ask how much it cost to get it fixed? I think I'll need to take it to Lex Tech rather than my normal garage for this one as it seems fairly complex.

[royoftherovers]

2 hours ago, TyrannosauRoss Lex said:

Thanks Peter. If it is the same problem that you had, may I ask how much it cost to get it fixed? I think I'll need to take it to Lex Tech rather than my normal garage for this one as it seems fairly complex.

I`d get it there pronto Ross.

To rev a car up to  and beyond 3000 revs in an  area where there are other vehicles, street lighting and presumably pedestrians would not enable me to sleep at nights.

[TyrannosauRoss Lex]

OK thanks for your helpful input. 

[royoftherovers]

19 minutes ago, Greer said:

So it needs to go for a run in Germany where there's no speed limit

Not quite right Alan.There are many speed restrictions along the Autobahn`s. They are not de-restricted throughout their entire length.

[Peter67]

In terms of the repair cost, in my case I did the work myself. I only had to replace bank 1 exhaust cam actuator as it was the one with that was sticking, they have a spring loaded unlocking pin and this was getting stuck so was intermittently throwing out the timing on that bank hence low power especially under load. If I recall the exhaust cam actuator was about €250 from Amayama. Once you have a reasonable manual and take your time and be fairly methodical its not too bad. The time consuming bit was correct diagnosis and then all the time for stripping the rocker cover. Once that was done the rest was quick enough. When you have the rocker cover off you should clean or replace the small VVT filter and test the oil control valve solenoid for correct operation, they are about €80 each (buy OEM for these as lots of spurious versions on eBay and they are a precision part). As I said in an earlier post get a good tech to monitor the 4 x cams under load and see what’s happening before diving in. 

Peter

[royoftherovers]

3 hours ago, Greer said:

Pedantic

 

And correct Alan.Your answer was wrong.

[TyrannosauRoss Lex]

3 minutes ago, royoftherovers said:

And correct Alan.Your answer was wrong.

If we're being really pedantic you should put a comma before his name. 

Anyway, please can we keep this thread related to the car. I've requested to get the car booked in to get looked at in just over a week so I'll keep you posted! 

Thanks to those who have been helpful to me. 

[PCM]

13 hours ago, TyrannosauRoss Lex said:

I've requested to get the car booked in to get looked at in just over a week so I'll keep you posted! 

Hopefully the garage will get it fixed for you! 

Good luck.

[TyrannosauRoss Lex]

Just to update this.....I spoke to Lex Tech and they said that if it is so intermittent there is no real point in getting it booked in unless it becomes more consistent, because you could throw money at looking into issues and spend hours not finding anything. A little frustrating but totally understandable. Having said all of that.....the car has been 100% fine for 4-5 weeks now....so very bizarre! It has its MOT due mid-November, so when it goes in for that I will also get them to check the radiator over along with all of the hoses etc and see whether they deem it sensible to change it or not. If it does "go" and leak into the gearbox, will I get symptoms such as engine overheating before any gearbox damage is done? I don't want to spend £250 (or however much it'll cost...possibly more??) on a new radiator and coolant change when it is totally unnecessary, yet if there is a very good chance that spending £250 WILL prevent something serious then of course I would do it.

Thanks again in advance.

[Peter67]

Yes. They have a point. Nothing worse than an intermittent issue to track down and of course it will never play up when they have the car in! ! You might get lucky and not have it occur to frequently. Stick with a good 0W20 oil and change it at the specified interval or less. This can have a surprisingly big influence on the VVT system performance and response. See how you get on.

In terms of rad replacement I did mine because it leaked at the top seam which is a common failure mode. I wasn’t aware of the known issue / risk of gearbox failure potential. The rads are not expensive and are easy to change out so its a good piece of mind perhaps. While there are aftermarket rads available such as from NISSENS beware they may not fit early cars (as I found out) so buy the Lexus / Toyota rad for a small bit extra. As an aside I find it odd that these cars don’t seem to have a low coolant level alert, something which I had on cars from the mid 1990s yet not on these cars. Unless you keep a regular close eye on your expansion tank you will not see the coolant level running low until you may hear a gurgling or whooshing noise from behind the dashboard signalling low coolant and air in the system.

Peter

[TyrannosauRoss Lex]

Thanks Peter. The car is currently running a high performance 5W-30 (ester oil)

https://www.opieoils.co.uk/p-68896-fuchs-titan-race-pro-s-5w-30-ester-fully-synthetic-engine-oil.aspx

I got that oil because of the cold start protection offered, and I got it at a good price, and it is still a recommended viscosity for the LS460 engine with the temperatures we experience in the UK. The weird loss of power issue was noted before that oil was put into the car though. I'm not sure exactly what oil it had in it beforehand, but it was serviced at a well-reputed Japanese independant.

Thank you very much for your insight RE the radiator. When it goes in for its MOT in around 6 weeks time I'll get them to have a look at the rad. That is somewhat ridiculous it doesn't have a low coolant level warning light? Is that true!?!? It is actually very hard to just casually check the coolant level because of all of the plastic coverings, you need to remove a lot to get a good look I think. Silly design in my opinion. I can see that there is fluid in there and it appears to be a little above the min mark, but it is hard to tell exactly where it is.

[royoftherovers]

 "it was serviced at a well-reputed Japanese independant."

Ross,If you can tell me the name,I can look if it is the list of Lexus and other Independents.