quensx

Have any of you noticed a slight vibration at Idle with the AC turned off? The Dealership told me that Lexus is aware of the issue and until they come out with a new update on the ECU, there is nothing they could do. I seemed to notice it on Warmer days with Auto off. The Idle drops to about 500 rpm or less and will notice some vibrations. Once the AC is turned back on, it will go back up to about 600 rpm and will not vibrate. The shop forman said that Lexus never assumed that the Auto will be turned off on the cars while driving. It seemed kind of like a minor issue, but I was wondering if anyone else is noticing the same thing.
Thanks for the input...

Silverpaws

I think that the shop foreman is trying to give you a snow job before the real stuff falls. I don't have the vibration and my idle speed without the air on is 600 to 800 rpm. The low idle speed is probably indicative of attention needed in some respect and I would keep insisting that Lexus should address it.

bsl888

The idle speed needs to be adjusted. 500 rpm is too slow, mine never drops that low. Take it to another dealer or talk to the service manager.

quensx

Really? Your idle never drops below 500? Even with the AC off. I noticed that it never drops below 500 on colder days, like in the morning, but in the afternoon, it always drops to 500 or lower when the Auto is turned off. Once you turn Auto on, or AC on, it will kick back up to 600 and no vibrations.
I spoke with the service manager and he told me, Lexus is aware of the Issue, but there is nothing that can be done.

Silverpaws

If you are idling at 500 rpm or less with vibration, can you idle the engine up to 600 to 800 with the accelerator and eliminate the vibration? If that solves the problem, I would think that the dealer could make a permanent adjustment.

quensx

The answer is yes... well sort of. When the car is in Drive and you let go of the brake and hit the gas, RPM rises and no more vibration. When it is at a complete stop and you hit the auto button, rpm goes to 600 and no more vibration.
When the AC is off, rpm drops below 500 to 400 sometimes and vibration is present. Shop manager said the car was not meant to be driven with auto off.
Is everyone in this forum driving their LS with Auto on all the time?
He stated that Lexus is aware of the issue and nothing can be done. I'm just a bit frustrated.

lexusnutt

The RPM's will rise when there is any electrical load applied.

Try it

Turn the lights on.
OR
Turn on the seat fan.

It is an issue I've gone around with at the dealer and no solution.

I just leave the seat fan on.

pkhuu78

Leaving the seat fan on is what i have to do to my car also. I have reported this problem to Lexus and several dealers in Southern California and I am getting the same answer. "it is normal, there is nothing that they can adjust or fix to improve it."

quensx

Wow!!! Turning the seat fan on does remove the problem. RPM is back up to 600 and no more vibrations.
You guys are awesome!!! Thanks Club Lexus members.

GammaLex

Mine goes to 500 but I dont have any vibration.

Silverpaws

Mine purrs like a kitten at 600-800 rpm with no air, radio, lights, seat fan, or anything else on. I checked it several times today. In fact average rpm was 700. It just doesn't seem right that rpm would go as low as 400 with vibration.

JFNash

Mine drops to 500rpm at idle unless the a/c or the lights are on.

The problem disappeared when I took the car back from the dealership after the VSR fix was done. 1000 miles later the problem came back.

From so much reading on this matter I concluded that nothing could be or should be done. I read so many suggestions from changing the air filters to cleaning the air sensor but always there was that feedback that the suggested solution just didn't work.

I decided to accept its existence and never let it ruin my Lexus driving experience.

quensx

hmm.. It is very interesting to hear that some cars w/ no load still have their RPM at 600-700, while cars like mine or some of the other members here have it go 500 or below w/ no load.
I wonder what makes other cars so different?

Silverpaws

I was wondering the same thing then it occurred to me that maybe the tachometers are not all accurate. Mine will definitely show 700 rpms idling with no load when engine is warm but I could not guarantee that it is accurate. I do know however, that the engine is smooth and quiet when idling.

I8ABMR

I had the same issue with my LS when I got it. There is a TSIB on it. They reprogrammed something in the ECU I believe. All I know is that it made a big difference. The idle is still smoother with the AC on because of the higher rpm, but it helped a lot. I would tell them that there is a TSIB.

Now that I think of it , I am pretty sure the TSIB may have been related to a hesitation issue with the LS when taking off from a dead stop. There is a solution to this