slickgt1

iTrader: (1)

I mean to say lights OR ac. I don't need both to be on to get rid of the vibration problem.

rominl

iTrader: (4)

ah gotcha, i was worried that you have an even more serious problem

slickgt1

iTrader: (1)

I'm glad I don't. I only see two issues with my car. This vibration thing, and the bushings seem to need an upgrade. That is all, knock on wood.

bmcdearis

I really don't see this as a major problem. i think this is basically lope from the cam. Think about it. This engine has more output per liter than a Z06 vette. All that really needs to be done is up the idle speed 100-200 rpm.

I think we are all spoiled by how smooth this engine normally is.

slickgt1

iTrader: (1)

Ok, and how would you go about raising the idle. Everything on this car is computer adjusted. If you are to open the Idle Air Valve, it will be only temporary. The computer will learn this and lower the idle. That is why the GS400 people are the only ones that can even adjust it slightly because the still have a throttle cable. GS430 is electronic/servo controlled.

Let me know if you know of a way to raise it and keep it there.

bazop

I too have a 01 gs 430, bought with 47k miles, bone stock. Noticed low idle prob about a month after buying it. I know have 55k and an injen intake and torquemaster plugs and cleaned the TB, but still does it. All I know is it is not a maintenance issue, like some of the other threads claim it is. It's annoying as hell to me.

slickgt1

iTrader: (1)

I have since called a whole lot of mechanic friends regarding this. A few have suggested that it could be the engine mounts. Ours are supposed to have this engine vibration suppressors mounted to the mounts. This is supposed to help with the vibrations. And this problem may not be idle related at all. They are saying that the idle is always adjusting, and the lexus is supposed to open the AIR valve for more air, if something is clogging it up or making it stick.

The problem is, why would the vibrations stop when the idle increased? Maybe those dampner things are working better, or maybe they are messed up and cannot compensate at that low idle anymore.

Anyone have any thought on this?

rominl

iTrader: (4)

yeah i have no idea too. on the gs400 it's easy coz' you can just adjust the cable a bit to increase the idle rpm, but on the 430 i don't know....

GRAND_LS 4

iTrader: (2)

Its all physics. When the rotation of an object equals the rotation of........... I know what it is, but cant really explain it that well. The same issue can be felt with driveshaft problems.

Panerai127

Guys I also have same issue and noticed it yesterday. I just bought the car 2 days ago. I have 01 gs430 with 84k. And you right, when the car has AC on it is ok and idle goes up and there is no vibration. When AC is off i have slight vibration on a steering wheel and the arm rest whem the idle goes down a bit, I mean it is not that bad, but for Lexus it is, I mean we bought this car for performance and quietness. I mean, I just sold my Bimmer to get into something as fast, but quieter, and more reliable. So, I would also take some suggestions. I do not know about these grounding kits. I am about to install a system in the car, maybe that will clear the issue. Also, SLICKGT1, I also have a problem with barrings I think, we have same millage on our cars. When I go over bumps going straight or turning slightly I get this loose feeling in the steering wheel that something in the front axle is not tight. Is that what you have?

slickgt1

iTrader: (1)

No not really, i have crappy worn original tires, and get tramline. It like it pulls with the bumps. Bumps are fine. I think you should do your control arm bushing. I am waiting for the Daizen polyurethane ones to come out and will get those as well. I like poly bushings so i want to get them just because. But that is definatelly the lose feeling you are getting. Also this lose issue should not be related to the vibration that we get during idle.

If the groungind kit does nothing for me, i will have my shop diagnose this. They have done some miraculous things for me before hand.

slickgt1

iTrader: (1)

I was also wondering if we have driveshaft bushings/mounts. Something there might be causing all of this. Hmm any ideas.

slickgt1

iTrader: (1)

OK for those that care. This is what I have done so far.

I have changed engine oil, oil filter, tranny drain and fill (twice). K&N air filter, denso iridium spark plugs, cleaned TB, installed the Teck grounding kit. Vibration is still there. But i have come up with a theory.

I have noticed that the vibration is only in drive. In reverse it is perfect. I think that this is due to some bushings/mounts being worn. I also think this is somewhere in the rear of the car. What i would like to ask you guys where there are bushings/mounts in the rear of the car. Like around the diff, drive shaft, something.