Lexuslsguy

Oil consumption will continue to get worse as the guides wear. I see that others have mentioned that they think it's normal for these engines to burn oil. This is up for debate. Some Toyota engines are known to burn oil and others are not. My 2014 does not burn any noticeable oil nor have my previous LS's.

The issue is not fuel related. This is wishful thinking. The problem is solely due to the valve guides and as the engine wears it will continue to get worse. Unfortunately, the only way to truly correct the problem is to replace the heads. The way Lexus solves the problem is by replacing the heads. The dealers know what is going on. It's just a very expensive repair and Lexus wants to spend the least amount of money as possible.

jfattibe

It does sound plausible but I'm in the same boat as doublebase, I don't burn oil and I only run Sunoco 93 octane, I also add Startron which is a fuel additive that helps clean everything in the fuel delivery system. I do believe, out of everything that it is an oil based problem. For me anyway. I like hearing all of the possibilities so keep them coming !!

roadfrog

My oil consumption is down to nearly zero. I am nearing 5k miles on this oci and the dipstick still shows nearly full. I may have to add 1 qt before the 6k mile mark, but might take it to 10k miles and see how it goes. As I've posted many times, I was adding about 1 qt per 1500 miles before I changed my oil regimen and used the Toyota Oil System Cleaner. My fuel selections have never changed.....91 octane from a mixture of top-tier stations, but mostly off brand stations and an occasional bottle of Chevron Techron (about twice a year).

Lexuslsguy

Maybe the lighter weight oil is helping the valve become more stable as it opens and closes. If this does the trick then keep it up. It is much less expensive then replacing the heads. The article mentions how inconsistent the hesitation can be. I think this leads people to think it may be fuel or maybe this or that.

roadfrog

Well crap......

After nearly a year and a half and four oil changes without issue, my hesitation cropped up out of nowhere today. Usual symptoms, EXCEPT that this is not after an oil change. I have cursed myself after all I've done and stated all this time.

I'll post whatever I experience in the coming days. I'm still convinced that this is oil related, but now.....who knows?

Lexuslsguy

I'm just surprised it took Lexus until 2013 to update the head design. That means 2007 - 2012 models have this potential. Oil weight I am sure can have an effect on the valves as they are being lubricated.The amount of play and amount of oil consumption are also related. This makes logical sense. But if the guides wear prematurely and allow play or slack the heads will eventually need to be replaced to correct the problem.

Doublebase

Please, oh please, don't let this be a valve guide problem. That's major. If that's what's wrong with mine, I'll be shocked. And here's why...virtually no oil consumption, it's not a consistent problem, not really a problem at all, I only experience it once in a while and I've been reading reports of LS 460 owners reaching 150-200k plus miles without issue. So I tend to think to think this valve guide problem isn't anywhere near widespread.

I can recall reading things about my Honda Accord...how the blocks were pourus and how coolant would leak into the crankcase. I was petrified, but it never happened, and it wasn't nearly as widespread as the article made it out to be. its something I'm going to keep an eye on, but honestly this is one of the tightest engines I've ever owned. It doesn't use oil, it never miss fires, stumbles, rolls, ticks...it just hesitates once in a while. It's something I can live with.

As for you, aren't you extending your oil change intervals a little longer than you normally would? It might be thinning out a little more than you'd like and the oil may not be coating the guides as thick as needed? A heavier weight oil might help things as well, if this is a guide problem, but it's a little premature for that.

Lexuslsguy

Here is the Lexus document. It pretty much says the same thing as the article. The repair is to replace the head when clearance is out of spec.

https://www.clublexus.com/forums/att...sb-0033-08.pdf

caha14

Sorry to hear, Chris. I hate to ask (and to sound like a broken record), but have you done the calibration update?

I've been relatively quiet on this topic lately, but began posting about it when I dealt with this issue 4 years ago. It was relatively early for this problem, and thus, I got to have interesting conversations at the dealer.

While indeed there can be a valve guide wear problem (requiring the cylinder head replacement part of the TSIB), the software update is not to be underestimated. As I have shared before, I had to persuade my dealer to do it, and everyone was blown away by the results.

The calibration update is not the panacea, but in the spirit of ruling things out systematically, it is a must, IMHO, and makes a world of difference, especially since '08 vintage 460s were 3 or 4 versions behind back in 2011.

If you've done it, moot point, of course...

satiger

iTrader: (1)

Holy crap....

Thanks lexuslsguy for sharing that TSB. This makes sense. Mine (2012 L) is not on this list (missed by few hundreds - build 06/2012). I don't have oil consumption or hesitation issue. However I am going to take this TSB to dealership and have them confirm/verify.

Affected models/VINs doesn't show build year against them. That means they continue to run certain production lines through 2012 without a fix even though it was identified in 2008???

Doublebase

I imagine what the flash does is it delays the engagement of the knock sensors, which of course isn't really fixing anything, but rather putting a band aide on it...which is probably fine. I think it probably depends on how bad the problem is too, because it seems as if there are plenty of people on here racking up miles on these cars without this issue.

I would think a high quality oil and perhaps sticking to the 5k mile change interval might not be a bad idea now. I don't think I'm going to chance running an oil too the point that the additives are low and filter is dirty, any longer.

roadfrog

I don't believe in jinxes, but I clearly did jinx myself

No, I haven't done the engine calibration update, but will do so when I get my recall done. I have no idea if it was done prior to my taking ownership of the car, but regardless, I'll have them perform it.

I can rule out the transmission. Last night I manually shifted the gears and the issue was still prevalent. I also selected "PWR" on the ECT switch, which didn't make a difference. The issue seemed to dissipate later into the evening and I'll see how it does later today when I go for a drive. When the problem goes away, I'll continue my extended drain interval closer to the 10k mile mark and get the oil analyzed. As I stated before, my 6k mile interval analysis came back great with no issues and lots of additive still in the oil.

With reference to the info above regarding valve guides, one would think that blue smoke and considerable oil consumption would be obvious. No? Again, my oil consumption is down to nearly zero after nearly 6k miles.

Devh

I'm sure it is an issue but I'm also sure it's not a widespread issue.
The only way it can correlate is if there is good amount of consumption in the presence of false knock associated with it which would lead you in that direction. I'm sure there are many like myself that doesn't have any unusual consumption.

If it was knock related it wouldn't be intermittent for long and it wouldn't follow an oil change as some reported.

I believe it can manifest as one of the known failures of the engine but not all engines will have this point of failure otherwise it would be more wide spread.
It's not uncommon for all engines that have one in thousands that have bad valve guides or valve seals that lead to an engine replacement but it doesn't mean all of the engines manufactured are bad.
Also just because an engine receives updated parts or design doesn't mean that the engines that came before it are doomed. All engines receive updates and redesign during it's lifespan before it's discontinued.

We are coming up on almost 10 years with many of these engines in service and there has not been one reported owner here that had their heads replaced because of this issue.

Trumpanche

RoadFrog,

Dang - you were my glimmer of hope! :-) Any steady low-rpm cruising before your hesitation episode? Also - I agree I don't think it's the transmission; my symptoms point back to engine every time.

DevH,
A few people have said they dealer replaced their cylinder heads. Their issues sounded less intermittent than what the rest of us describe, though. Whenever my car's at the dealer it behaves fine.

thomastan said they did in this thread: https://www.clublexus.com/forums/ls-...il-change.html

and

glenneagle and WhitBaby both said they did in this thread: https://www.clublexus.com/forums/ls-...-problems.html

Devh

I think the best thing to do is data log and when the event occurs you can then see what has transpired.
If knock is observed which retards timing then it could very well be this issue.
If timing is retarding or not advancing as it should in the absence of knock then it;s possibly the VVT.
You should data log using a blue tooth adapter and a laptop or smart phone.