congrats if it is lol. share the knowledge when you find out what it is.

 

So what's the verdict?

 

Good thread, I haven't noticed this yet on mine, thanks for the alert.

 

I have not had the time to pick it yet. Still driving the loaner GS300.
Maybe tomorrow.

 

Ok. Have it back.

BS!!

Problem is as bad it was. I have called up Lexus and the district Service Mgr is now involved. Next week they will arrange for another inspection at another dealer. Let us see how it goes.

 

After reading this thread I notice the same sound, but it is slight, nothing that I would report to the dealer but it is annoying. I also realize that I have been sometimes going to neutral while stopped to quiet the sound. I don't see this as a big deal but I do have to wonder why the engine/tranns seems to go under such stress to run in a braked position?

 

you have to be more discerning. I did not pay a fortune to have a vehicle that idles worse than a Pontiac G6 4-cylinder engine. No wonder Lexus gets No.1 in JD Powers........

 

I was reading other Lexus boards and it appears that the Idle Air control Valve IACV might be the prime culprit for its inability to maintain idle speed and thus a smooth idle.

 

If it is the IACV, that my explain why I get the vibrations are more noticeable for me on cold nights at the track (given all my mods, especially air and exhaust).

 

I only have the vibration in the steering wheel while stopped at a light in drive. It's also only during the winter months. I never feel it above when the temp outside is above 45 degrees.

 

Here is the latest run down of when the vibration occurs:

1. Vehicle is throughly warmed up
2. Light switch is on Auto or Off
3. Gear selector is in D
4. Foot on the brake pedal
5. AC is switched off

At this time, the idle will drop to maybe 600 and the vibrations and the ensuing drone in passenger cabin is unbearable.

Now look at the changes in some of the variables and how it affects the scenario:

#1:
========
If I switch on the lights (not on auto), the idle speed goes up to ~750 and once again idle vibration is there, but minimal.


#2:
========
If I take the foot of the brake pedal and instead use the e-brake, idle speed goes up a bit, ~700-750 and the vibration is there, but minimal.


Now what do you think is the probable cause?

In my opinion, the mounts are certainly worn as I can feel some vibrations in any case.
But the dropping of the idle speed and the resulting increase in vibration is of concern here.

 

Your description seems to indicat your idle is set WAY low. Unlike a straight-6, the V-6 is in inherently unbalanced engine and will not be nearly as smooth - particularly at idle. Turning on the AC or engaging an electrical load will pick up the throttle slightly, as designed, partially relieving the problem - as you've experienced. If you set your idle adjustment to a minimum of 700-850 (check your manual) the problem should largely disappear.

 

I thought i might contribute, im seeing the same problem in my 2000 Solara v6 which uses the same engine, if its warm outside its smooth but under 40 i feel the vibrations in the steering wheel, and if its really cold my seat vibrates too.

 

Does everyone here have 750 rpm at idle?

With my mods, I am slightly higher, maybe 850 I guess.

 

Can I even adjust the idle? I thought this was controlled by the computer via the IACV.

By the way, what is the recommended idle at "P" and at "D"?