Just wanted to give an update to tall.. I decided to bring my car into Lexus to find out what the actual problem was. After a day of inspecting my car, i finally got the call from the Lexus Services department. It ended it being my brake actuator. Finally got my car back, no vibrations of any sort and drives like knew! Thank gd I bought had an extended warranty for this car. Otherwise it would have costed my an arm and a leg!!

 

I have this same thing happening. Thanks for the update on your recent post
FWIW, I've been in a mid 2000's Camry that had the same thing going on

 

To add to this thread, I noticed three things this morning upon starting my car:

1and 2. The Malfunction Indicator Lamp lit, along with the slip indicator. I read somewhere that when the MIL lights, VSC is turned off , and thus the slip indicator lights.
3. With the A/C off, in Drive, and not moving, the idle RPM shows as just under 500 rpm, there is a slight vibration felt in the steering wheel and driver's seat, and there is a low sound that corresponds with slight vibration. I'm not sure where the sound is coming from. Turning on A/C results in the idle increasing to around 700 rpm, and there's no vibration or associated sound

None of these three things has happened before with this car I purchased a little over 3 months ago. I brought it to my local Lexus dealer, and I'll report on the status. I find it difficult to believe the vibration is normal, as the car has never done that before. I've used the car numerous times with no A/C.

 

The dealer tells me the problems are related to the camshaft circuit being open, and the fix is to reprogram the ECU. The below TSIB L-SB-0142-11 seems to describe the MIL situation with my car:

http://www.revbase.com/BBBMotor/TSb/...dPdf?id=172396

I'm told that should fix the low idle issue, too. I hope that's correct.

 

I forgot to mention that when I brought the car to the dealer upon turning off thr engine and the service advisor turning it back on, the MIL and slip indicator no longer stayed lit. There's some sort of data logging function, however, so tne error code was viewable. Indeed the ECC was recalibrated per TSIB L-SB-0152-11.

Neither the MIL nor the slip indicator has come on, beyond the momentary display when the car is started. The idle while stopped and in drive with A/C off seems to be at 500 rpm, but no lower. The vibration is still present, but greatly reduced. The harmonic(?) sound hasn't recurred.

 

Sorry to resurrect these threads, but here is another one that kind of mirrors what I'm "feeling."

I could just be OCD as the vibration is almost imperceptible, but again, it only happens when the RPM drops to 500 and that in itself is rare. No noise, just a slight vibration.

Other than that, it's dead silent at idle in both scenarios.

Another thread mentioned my car has to learn something (a battery change thread that I won't bump)?

Again, kind of leaning towards taking my car to the dealership, but if this is normal, I'll just wait and see. The other solution is to just keep my AC on, even in heat mode (I turned it off), as any load seemingly prevents idle speed from dropping below that 700ish mark.

 

So I talked to Lexus service tech about my idle and slight vibration and he said it was normal.

Ok.

He said our cars are drive-by-wire and the, and I quote, "learning" computer controls the throttle body. He said it takes a bit learn, whatever it is learning lol, and should lesson the more I drive.

Well today, it didn't happen at all, no RPM drop, even with heaters off, so eh, who knows.

So in summary, there's nothing they can do about it or there's nothing they are willing to do about it based on my brief conversation.

I'll continue to monitor and see how it goes.

Again, it's almost imperceptible, but I do notice it. It really doesn't bother me, but hey, it's brand new.

 

Well, the low idle speed (and associated slightly perceptible vibration) is completely gone. It's now idling slightly above 600 or so RPMs under all stopped conditions after the car reaches nominal operating temperatures (while in drive), slightly higher while warming up.

I took delivery at 68 miles and it's now clocked in at 250 miles or so. All minor trips of mixed driving, some freeway. Never took the car over 3000 RPMs during that time I think. Still trying to break it in (yeah I haven't driven much as I got the last two weeks off).

So I guess I taught that computer a thing or two lol.

In any case, it's rather interesting how that works. I guess I can look forward to this every time that computer resets, assuming it's not flashed into some permanent memory bank somewhere.

 

I thought about chiming in a few times. I totally agree with everything you have experienced and done. Nearly all new cars are ran by computer and react similar to your experience. I have even had this happen to my LS. my idles has been anywhere between 1100 and 400. Those are the extremes while 600-800 is the typical. I have gotten the slight vibration before and done a reset. NOTE, if you ever try to reset, disconnect the negative and this is the important step, do something to put a load on the system. Pushing the brake to turn on the brake light. This will take away any charge that capacitors in the system my have. Wait a minute. And reconnect. When you start you car it may act strange or even die. This is typical as it is learning the air fuel mixtures. It starts with factory default program and quickly learns. It will get close right away and slowly develop the best fuel air mixture algorithm. Again this is typical for any car in the last 20 years. What happened to you is nothing I would call out of the originally or of major concern. Your issues might have been started by a dirty sensor and your car was trying to compensate Dirty 02, fuel, or air sensor. I think things like this happen to cars quite often. I think it's just the LS owner is more in tune with their car than the average driver.
I am not a mechanic or expert. Just stating what I beleive or experienced.

 

 

I just purchased a used 2010 LS460 and found this thread after searching for the topic discussed here. I'm also a sound designer, so I may be able to add an element to this that may help others who stumble upon this thread, thinking the worst. I've also owned the LS430 and LS400. Both those older models never had this issue for me. After taking my LS460 to 2 different mechanics with no answers, I am inclined to conclude (based on my sound design experience) that this is a low frequency issue. Think of it like a subwoofer holding a constant sinewave at a specific frequency that will rattle everything in your house. The normal idle frequency for the 460 seems to hover at 52 Hz with no A/C on in park. When you put it into drive it drops to 45 Hz at idle. With A/C on it then drops down to 35 Hz at idle. To give you an idea of how this is affecting your vehicle, click on the following link to hear a test tone at 35 Hz (you'll need to play it back on subs to get the full effect): and in conclusion, the engine idle RPM seems to be the culprit mainly when the car is put into drive or the A/C is used. Those frequencies turn the metal frame of the car into a giant resonator which, frankly sucks. The "fix" would be to set your idle at a slightly higher RPM so when you put it into drive it doesn't drop in Hz so low.

 

Disappointed in the ls. Just started to have this idling issues too and couple more. Maybe my expectations are high from lexus specially the ls, but i am noticing alot of problems from it.

 

So what is the normal rpm with the ac off?

 

It could be your engine mounts.

I replaced all 3 of my engine mounts. My car no longer has any vibrations at idle. It is worthy to note when diagnosed at the lexus dealer at around 160k miles they claimed the engine mounts were fine. The mounts are not your typical engine mounts the rear mount is a combination of fluid and rubber. The front 2 mounts felt more like pure rubber. Although the way the front 2 mounts are encased in metal I wouldn't be surprised if they also had some hydraulic dampening action going on inside. Once I removed them it was obvious they were all worn / broken internally. My vibrations would come and go with engine idle rpm changes. The new mounts completely eliminated the vibrations resonating through the car. I suspect in a number of years as the mounts age I will start to notice subtle vibrations again.

https://www.clublexus.com/forums/ls-...l#post10679075

 

I know it may sound a little weird but i found the fix for this is to replace the Battery management sensor. Its really easy to find just follow tge negative battery cable to where it mounts the the body. Its a black box with one 4 wire connector going to it. Mine had rumble and a check power control message. After fixing the power control the rumble went away aswell. Hope this helps someone i know the car is getting old. It could be combines with aging engine mounts but i think the battery controller controlls rpm a little to control alternator output. I think thats the reason for the odd loss of RPM and if the AC trick helps i think this is your problem.
Edit: It came back, now im thinking it has something to do with the battery tho. The vibrations go away aftet driving it for 5 or so minutes. Can anyone tell me weather the engine mounts or brake accuator actually fixes this? I just find it odd that its smooth as butter after it drives for a bit. It does look like the idle rpms are a tad over 500 when it works well and just under 50p when it rumbles. Any advice would be appreciated.