Hesitation on Acceleration
09-27-16, 11:01 PM
#303
any thoughts about the following: 2007-12 models may need new cylinder heads to resolve engine hesitation (33-08).
found it embedded below:Service bulletins
2007-09 2WD models with a rattling/knocking from the rear suspension might need designed rear springs installed (58-09).
2007-10 cars may require redesigned suspension arms to eliminate a knock or clunk over bumps or when braking (21-12), and they might need a windshield deflector molding if there is crosswind turbulence inside the cabin at highway speed (33-09).
RWD LS 460 models from 2007-11 have two issues: a newly designed radiator cooling fan assembly prevents overheating (29-11), while vehicles with a worn out air suspension that rattles or knocks when going over bumps have updated parts available (138-11).
2007-12 models may need new cylinder heads to resolve engine hesitation (33-08).
2009-12 AWD models may need a software update to prevent a shudder between 30 and 75 mph (13-12).
found it embedded below:Service bulletins
2007-09 2WD models with a rattling/knocking from the rear suspension might need designed rear springs installed (58-09).
2007-10 cars may require redesigned suspension arms to eliminate a knock or clunk over bumps or when braking (21-12), and they might need a windshield deflector molding if there is crosswind turbulence inside the cabin at highway speed (33-09).
RWD LS 460 models from 2007-11 have two issues: a newly designed radiator cooling fan assembly prevents overheating (29-11), while vehicles with a worn out air suspension that rattles or knocks when going over bumps have updated parts available (138-11).
2007-12 models may need new cylinder heads to resolve engine hesitation (33-08).
2009-12 AWD models may need a software update to prevent a shudder between 30 and 75 mph (13-12).
09-27-16, 11:08 PM
#304
Driver School Candidate
Join Date: Sep 2015
Location: NEW SOUTH WALES
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
My history of this was:
2014 - bought 2007 LS460 with no problems
2015 - after oil change problem occurred and lasted the year, whilst getting gradually better
2016 - after oil change the problem disappeared
My mechanic is an independent Lexus specialist and has been working on Lexus V8s for over 20 years. When I mentioned the problem he said it sometimes happens when there is too much oil in the engine and so he suggested putting a bit less in. Problem disappeared. This would be consistent with:
a. The problem occurring after an oil change.
b. The problem resolving gradually as oil gets used up.
Yet another anecdotal solution I'm afraid
2014 - bought 2007 LS460 with no problems
2015 - after oil change problem occurred and lasted the year, whilst getting gradually better
2016 - after oil change the problem disappeared
My mechanic is an independent Lexus specialist and has been working on Lexus V8s for over 20 years. When I mentioned the problem he said it sometimes happens when there is too much oil in the engine and so he suggested putting a bit less in. Problem disappeared. This would be consistent with:
a. The problem occurring after an oil change.
b. The problem resolving gradually as oil gets used up.
Yet another anecdotal solution I'm afraid
09-28-16, 08:18 AM
#306
Lexus Fanatic
The replacement of heads has not worked in solving this issue. It's also an expensive procedure.
It is clear that oil is the common denominator. I believe it is associated with going to a synthetic from a dino based oil. This is the only theory that seems to follow logic so far.
It is clear that oil is the common denominator. I believe it is associated with going to a synthetic from a dino based oil. This is the only theory that seems to follow logic so far.
09-28-16, 11:39 AM
#307
The replacement of heads has not worked in solving this issue. It's also an expensive procedure.
It is clear that oil is the common denominator. I believe it is associated with going to a synthetic from a dino based oil. This is the only theory that seems to follow logic so far.
It is clear that oil is the common denominator. I believe it is associated with going to a synthetic from a dino based oil. This is the only theory that seems to follow logic so far.
Oil is a big one, as evidenced by your own experience/testing with your car. Thing is, my dealership has encountered hesitation even when going from synthetic to synthetic, as I may have mentioned earlier.
Even more interestingly, my 460 was delivered to me with dino 5W30 that the selling Jag dealership was "kind" enough to unnecessarily change (car had just had 40k service at Lexus before trade-in, but anyway). The car had zero hesitation. I then changed the oil to 0W20 (synthetic) and again, zero hesitation. Not once.
A couple of months later, my battery died and was replaced. Still, zero hesitation. My wife took the car for one day. I got it back, and within a day, I had a slight hesitation. This hesitation only became worse over the course of a month, reaching levels of danger just shy of what you have described (i.e., I had scary encounters, but the car still somewhat responded, at least eventually).
The ECU calibration update virtually eliminated the issue. Evidently, in this case, something else (outside the realm of oil) was the trigger. As I've said before, I don't know what specific parameters changed, but I can't imagine the ECU was reprogrammed to "ignore" the knock sensors all of a sudden. The throttle was more responsive, and gear shifting also became more linear and a bit smoother. This is why I always suggest the update; it's a step closer even in cases where another inherent issue is at play.
This is one of those fascinating engineering conundrums, for sure, albeit not fun for folks who haven't been able to get resolution.
Last edited by caha14; 09-28-16 at 11:44 AM.
The following users liked this post:
DrQuality (08-07-21)
09-28-16, 05:11 PM
#308
Pole Position
Not to muddy the waters further, but for what it's worth... Acknowledging that my 460 hesitation experience was "smooth sailing" relative to others' (i.e., I can only imagine the frustration), it still seems like there are multiple causes for spark timing being retarded/suppressed, as I have opined before.
Oil is a big one, as evidenced by your own experience/testing with your car. Thing is, my dealership has encountered hesitation even when going from synthetic to synthetic, as I may have mentioned earlier.
Even more interestingly, my 460 was delivered to me with dino 5W30 that the selling Jag dealership was "kind" enough to unnecessarily change (car had just had 40k service at Lexus before trade-in, but anyway). The car had zero hesitation. I then changed the oil to 0W20 (synthetic) and again, zero hesitation. Not once.
A couple of months later, my battery died and was replaced. Still, zero hesitation. My wife took the car for one day. I got it back, and within a day, I had a slight hesitation. This hesitation only became worse over the course of a month, reaching levels of danger just shy of what you have described (i.e., I had scary encounters, but the car still somewhat responded, at least eventually).
The ECU calibration update virtually eliminated the issue. Evidently, in this case, something else (outside the realm of oil) was the trigger. As I've said before, I don't know what specific parameters changed, but I can't imagine the ECU was reprogrammed to "ignore" the knock sensors all of a sudden. The throttle was more responsive, and gear shifting also became more linear and a bit smoother. This is why I always suggest the update; it's a step closer even in cases where another inherent issue is at play.
This is one of those fascinating engineering conundrums, for sure, albeit not fun for folks who haven't been able to get resolution.
Oil is a big one, as evidenced by your own experience/testing with your car. Thing is, my dealership has encountered hesitation even when going from synthetic to synthetic, as I may have mentioned earlier.
Even more interestingly, my 460 was delivered to me with dino 5W30 that the selling Jag dealership was "kind" enough to unnecessarily change (car had just had 40k service at Lexus before trade-in, but anyway). The car had zero hesitation. I then changed the oil to 0W20 (synthetic) and again, zero hesitation. Not once.
A couple of months later, my battery died and was replaced. Still, zero hesitation. My wife took the car for one day. I got it back, and within a day, I had a slight hesitation. This hesitation only became worse over the course of a month, reaching levels of danger just shy of what you have described (i.e., I had scary encounters, but the car still somewhat responded, at least eventually).
The ECU calibration update virtually eliminated the issue. Evidently, in this case, something else (outside the realm of oil) was the trigger. As I've said before, I don't know what specific parameters changed, but I can't imagine the ECU was reprogrammed to "ignore" the knock sensors all of a sudden. The throttle was more responsive, and gear shifting also became more linear and a bit smoother. This is why I always suggest the update; it's a step closer even in cases where another inherent issue is at play.
This is one of those fascinating engineering conundrums, for sure, albeit not fun for folks who haven't been able to get resolution.
03-14-17, 01:46 PM
#309
My LS has just starting experiencing symptoms of this, 96K miles. While driving it will randomly become sluggish...almost as if the transmission when into neutral for 1-3 seconds and then very slowly gain momentum/power as my foot stays on the pedal. I will come to a stop light and once the light turns green and I begin moving again, the car seems to run fine. Again it occurs randomly but appears to be happening more frequently. I should also note very seldom the car will behave as if there is a misfire at idle...this behavior maybe happens once every 3 months if that. In fact I first thought the sluggish feeling I first noted was maybe due to the misfire becoming worse.. bad plugs etc...but I stumbled upon this bulletin and now I'm note sure if I've got two issues.
Looking over the cars entire service history it doesn't appears anything related to L-SB-0033-08 Rev 2 Bulletin was ever completed. Does anyone know what the cost is to recallibrate the ECM and 2nd: the cost for replacing the valve covers, cylinder heads, intake and exhaust valves?
Looking over the cars entire service history it doesn't appears anything related to L-SB-0033-08 Rev 2 Bulletin was ever completed. Does anyone know what the cost is to recallibrate the ECM and 2nd: the cost for replacing the valve covers, cylinder heads, intake and exhaust valves?
03-14-17, 02:05 PM
#310
I agree it's definitely related to the oil. I had mad hesitation after every oil change. But when I had my transmission fluid flushed and changed at Lexus. I had mentioned the problem to my tech. Surprisingly he had never heard of it ?? But would check into it. When I picked up my car he said he "flashed" the transmission. He said if that didn't do it after the next oil change to let him know. I changed the oil the next week and NO HESITATION !!!??? I would suggest having this done if you have exhausted other options, it worked for me.
The following users liked this post:
DrQuality (08-07-21)
03-14-17, 03:19 PM
#311
I noticed the problem on my '07 starting around 40k miles - and always after an oil change. It would go away after a few hundred miles, which would cause me to forget to ask about it during the next service. I stumbled upon TSB L-SB-0033-08 - and shared it with the Lexus SA when having the oil changed at 55k miles. The technician "flashed the ECU" and I have not had the hesitation problem in the 3 years/30k miles since the update. So it definitely worked for me. Lexus did not charge me for the update, even though my LS was past the 6-year engine warranty mark. If I recall that one of the steps to determine if the vehicle needed more than an ECU update, the technician was to pull one or two of the spark plugs to look for fouling. If no fouling was found, the ECU update was all that was required.
The following users liked this post:
DrQuality (08-08-21)
03-14-17, 09:20 PM
#312
I've dropped the car off at my local dealer...they are going to flash the ECU per the service bulletin and plan to give the car back to me with instructions for me to update them if I have continued problems. I was told that normally the re-flash solves the issue. I'm going to ask tomorrow exactly what the re-flash does. I was also told if the cylinder heads need to be replaced it is a $15K job. Wow.
Knowing the car has 96K miles and never had the spark plugs changed, I wonder if I should just call them tomorrow and instruct them to also do this.
Knowing the car has 96K miles and never had the spark plugs changed, I wonder if I should just call them tomorrow and instruct them to also do this.
03-14-17, 10:41 PM
#313
Lexus Fanatic
I've dropped the car off at my local dealer...they are going to flash the ECU per the service bulletin and plan to give the car back to me with instructions for me to update them if I have continued problems. I was told that normally the re-flash solves the issue. I'm going to ask tomorrow exactly what the re-flash does. I was also told if the cylinder heads need to be replaced it is a $15K job. Wow.
Knowing the car has 96K miles and never had the spark plugs changed, I wonder if I should just call them tomorrow and instruct them to also do this.
Knowing the car has 96K miles and never had the spark plugs changed, I wonder if I should just call them tomorrow and instruct them to also do this.
http://www.ebay.com/itm/TOYOTA-LEXUS...hX9clJ&vxp=mtr
03-15-17, 05:01 AM
#314
I've dropped the car off at my local dealer...they are going to flash the ECU per the service bulletin and plan to give the car back to me with instructions for me to update them if I have continued problems. I was told that normally the re-flash solves the issue. I'm going to ask tomorrow exactly what the re-flash does. I was also told if the cylinder heads need to be replaced it is a $15K job. Wow.
Knowing the car has 96K miles and never had the spark plugs changed, I wonder if I should just call them tomorrow and instruct them to also do this.
Knowing the car has 96K miles and never had the spark plugs changed, I wonder if I should just call them tomorrow and instruct them to also do this.
I use good oil pour in gas additives and used a oil additives and it still run like a top. I don't think the additives help much but i just feel better using them.
Good luck!
The following users liked this post:
DrQuality (08-07-21)
03-15-17, 10:16 AM
#315
Lexus Fanatic
I never had the calibration done and have not had any hesitation for nearly 3 years and 6 or so synthetic oil changes. This is where things are interesting. Clearly oil is the issue, but how does it associate with the transmission re-flash? Engine ECU, sure (I guess), but trans? I dunno. It's an interesting problem, but it seems the issue has gone away through any combination(s) of our remedies.