I would not know what everyone is running at the moment, and weather might alter it slightly.

I noticed that by tightening the accelerator cord in the throttle body that this 'nudged' ever so slightly upward.

 

my other vehicle is a Mazda6 V6 and you should see it idle. It would make you think that the engine is not even running, and the idle does not even fluctuate when I start on the lights or defroster or any other electrical item and it has 38000 miles on it, compared to the 47000 miles on the RX300.

 

Both my RX's and the 3 loaners I drove all had this slightly rough idle. Being subjective this is a tough item to nail down on a discussion forum like this. Most owners will claim they don't have the rough idle until you sit in the car with them and point it out to them. My Olds Alero v6 does idle much smoother.

 

per Lexus press releases, NVH means NO Vibration & Harshness.

They have to step up find a fix for this problem. The lexus cust rep is now involved and let us see where it goes.

 

A stock RX300 should not suffer. I used to remember before modifications that sometimes I would wonder if the car was even on and would actually do that nickel balancing deal on the engine block (I think Rolls Royce used to do something similar).

Now the car gets it vibrations...seems like pent up with anger and ready to go.

 

I also have same problem while stopped at a light in drive only when the outside temp dropped below 45 degrees. My RX300 is also AWD.

 

Bad motor mount and/or bad idle control valve would cause a rough idle whether in 'D' or 'N.'

This problem only occurs (in most cases, anyway) when in 'D' -- it does not occur in 'N.' In fact, it completely goes away when in 'N.' This leads me to believe it may be transmission related rather than engine related, although it could have something to do with the engine under certain engine loads....

I may be wrong on this, but I doubt it.

 

Probably one of us should see after an ATF drain & fill or flush whether we notice anything. I have to exclude myself given my modifications and I notice vibrations.

However, I just finished my second drain and fill on Thursday night with my last one on January 23rd and one more to go and the RX runs smoother on the road and at the track. I hear the shifts but cannot feel them and the vibrations are not as much. My dad took a drive tonight and he had driven it down here in December and could definitely notice the decreased vibration.

 

I had the problem both before and after an ATF drain and fill. I didn't flush it though....

 

anyone have any updates?

 

My vibration has really gone down to practically nothing.

 

Still pushing with Lexus.....dealer wrote on work sheet -"unable to resolve issue- no known resolutions"

wtf am I supposed to do now?

 

thats basiclly what i got and now my lex is out of warranty.

 

mine is still under warranty.....CPO

 

Any update to this issues? This is what my mechanic did to test the noise. He had me in the car in "D" and step on brake, with a jack, he slowly lift the car and you can hear the humming noise go away when the car is jack up a little. What does this mean? Is it the engine mount or not? I'm lost, my car now has 110,000 miles and I'm not sure if I care anymore but i thought i will give u guys the results of my mechanics test.