whenever i come to a complete stop my sc starts to shake why is it idling so much?

 

have you tried cleaning your throttle body?

 

Did you just buy your car used, or have had it since new and started doing it? How many miles? Does it do it hot, cold, or both? A/C on or off? Provide more info.

My car has never been butter smooth since day 1. I can feel the engine shake a bit when cold, and I can hear and feel a kind of rhythmic 'hummmm hummmm' at idle when hot and using the A/C, even though the tach needle stays steady. Neither of my previous three 4.0 V8 Lexii (LS, GS, SC) did that, so maybe Lexus didn't spend enough money properly balancing the 4.3 after it's displacement increase. It's so minimal it doesn't bother me, but surprised me nonetheless. And yes, it's supposedly normal.

Hey Rominl, how do you go about cleaning your TB? I didn't think you'd have to do that with anything less than 100K miles. Just curious.

 

well it's hard to say, sometimes you don't know what gets in. but yes supposedly you don't have to do it until veyr high mileage. the 430 engine shouldn't have low idling problem, though i think i have seen some in teh GS forum. so i suggested cleaning the TB

on a lot of gs400 though, idling problem is common (knock on wood)

dub, just curious, when you talk about the idling problem, is your AC on? if no, then try to put it on, and see if you still have the problem?

 

I have an '02 which I purchased in '03 and have experienced rough idling several times. It has been repaired, with varying degrees of success, by reprogramming the ECU (twice), cleaning the fuel injection/throttle body system, and replacing the engine mounts. Only after the engine mounts were replaced did the problem go away. I must say that the rough idle didn't really bother me but it did seem out of character for the SC. Hope this helps.