NJerseyDan

There was like a small weight attached to my exhaust attached with a rusted out tab. Busted off on me years ago. Would that have been a resonator?

awww man! that's a bummer. I was really thinking we were on to something there:/

I've seen online you can buy bearing kits for a lot of alternators. So. That's good.

It will rattle loose trim or keychains, or loose change. I've heard it rattle just about everything in the car at some point. Used to rattle my license plate occasionally, so I put foam strips on the back of it. It's definitely not a loose interior part. Or anything under the dash. It seems to me to come from the engine, but it carries through the whole car. And it's just sitting still, not actually driving o our famous topnotch jersey roads, and circles, and jug handles :) ha -You know you're in jersey when they put up a sign for a pothole, rather than fix the pothole.. Schumif, did you ever check out the alternator?

I'd heard the same about the timing belt- one tooth off will throw a code. But I didn't notice any change after mine was done, anyhow- vibrated before and after. I had Lexus do mine. Pat, I don't think our Rex's have EGR. But we do have a PCV valve. And mine was fine when I checked it. Shumif, I've never checked any pulleys, but I do have a occasional belt squeal when the ac kicks in cold weather, despite both belts being adequately tight, and in good condition. I'd wondered before if a bearing could be bad. So that's interesting... you might be onto something there. I'd written off the torque converter because those two tranny shops told me it wasn't tranny related. But I did read in a forum a while ago about an improperly installed torque converter causing vibration. And the tranny/TC in our truck is prone to an early grave. Danfox, I don't know a whole lot about the timing system. Could a little bit of slack in the belt cause a problem? My engine has gotten noisier also. Theres a sound that I would describe as a high speed chatter. I was thinking the valves needed adjustment. That's what it sounded like to my untrained ear.

shumif, I don't think I ever changed it. But I do remember climbing under and checking it out, a few years ago. And I'm pretty sure it was the braided steel, flex type connection. And I think I wrote it off after the two exhaust shops told me the problem wasn't exhaust. Probably worth a try though. Seems some of things I've tried, have worked for other Rex's. Like Lenore up there had the driveshaft supports done, and straightened it out. I also remember seeing on a forum that some guy had a sensor changed at his dealership, and that fixed it. He didn't say what sensor it was, and he has never replied to any posts on that thread since.. sob

Hey buddy, I've got an 01' 300, that I've had for about 6 years. I can save you some time and effort on yours. I bought it with 60K and it started doing the vibration thing around 75K. I've changed both motor mounts, and the tranny mount. Put a New IACV in. Had the Injectors cleaned at PepBoys on their super duper machine. Changed the Drive shaft Support bearings. Replaced that upper engine support strut. Had two exhaust shops tell me the problem wasn't exhaust. And two transmission shops tell me it wasn't transmission. Taken it to 3 lexus dealers, to get different opinions, and wrote a letter to Lexus. When It's particularly annoying I drive around with my auto scanner plugged in, watching live data. But I haven't seen anything on there to point to the cause. Like your Rex, If I give it the slightest gas, it will smooth right out. I've scoured these forums off/on for years now trying to find a solution to it! I give up for a while, then I come back. I've been considering changing the Harmonic Balancer. There's a company called Fluidampr, that makes some super high tech ones, but unfortunately not for our car. But if I find something like that, I may try it out. I've also been doin some research on ECU remapping. If you could just raise the idle 60rpm or so, I think it would eliminate the vibration(adjusting the screw on the throttle body will not do it). Other than that annoying vibration, my Rex has been a great car. Put on 100K since I bought him.

I've been thinking about doing it, because I've tried pretty much everything else to get rid of my rough idle. I have a Haynes Manual that gives you the steps. Heres pic from my alldata subscription. Hope it helps. Filter is like 20$ and I'd get the strainer too, while you're in there. I think they're 20$ as well. Why are you changing this ?

I might be interested in your NAV ECU. I tried messaging you on here but it wouldn't let me. don't know why. Can you email me at Dan.canales@yahoo.com

For those of you interested, I just spoke to the mechanic foreman at Cherry HIll, Lexus(NJ). I was going to ask him if he could give me the default values to look for on my scanner. But, he told me that if those values were off even a little it would trip and CELight. I told him about the diagnosis I received there back in the summer- about the dirty speed sensors causing vibration while standing still. He completely agreed that's incorrect. I'm glad he didn't try to defend the diagnosis just because it came from his shop. So, he gave me his email address and told me he'd ask around and see if he could figure it out. So I wouldn't hear from him til next week. So. Lexus is back on the case. fingers crossed. If he tells me it's warped rotors I'm never going there again :) Update November 29, 2010. So Frank, the Mechanic Foreman of Cherry Hill Lexus emailed me back. Here's his reply. "I have had complaints about that idle vibration, as has Lexus, but no fix at this time. I will save this email, if I hear about anything that could fix your car, I'll let you know." I've seen other people say they have gotten this response from Lexus, I just couldn't believe they would say this to me. Lexus is openly admitting that they just don't know how to fix this!! Unbelievable. Update January 27, 2011 I've given up on Cherry Hill Lexus helping me. So I took Rex to my local TiresPlus where I've gotten my past two oil changes. I had mentioned the problem and the guy there told me their head mechanic was a wiz at diagnosing. They had my car for two days and couldn't figure it out. So instead of charging me for the full $100 diagnostic package, they only charged me $20 for some basic inspection package, because they felt bad about not being able to help. Thats the TiresPlus in West Berlin, NJ. So after that I decided to go straight to the source. I emailed Lexus through their website two weeks ago. They wanted me to take Rex back to Cherry HIll Lexus for a Physical Inspection. I told them about the bad diagnosis I got from them last time I was there. The latest email I received from Lexus this Monday said that they will be contacting Cherry HIll and pursuing the matter further and will contact me within five business days. I've got this fantasy in my head that they contact me and say that for all my trouble they're just going to give me a new RX450H. And what color would I like? Ha ha. a guy can dream, huh?

Tom C, I just spoke to Pat Goss. Nice guy. He didn't have an answer for my specific vehicle, but I told my situation and everything I've done to my car. And he says it's probably something with the timing. I had my timing belt changed a year ago, and he says if they put it just one tooth off then it cause what I'm seeing. I've also got a OBD reader that also gives all the data coming off the vehicle computer. he's saying I can get the values that I should be seeing on there off the internet, and then compare them with what I'm seeing. So thanks man. You gave me another door to try:) Here goes

Paul- thanks for the input man. I'm thinking it's probably something with the fuel/air too. Thing is, when I first stop the vehicle it idles fine. It's smooth. So the motor mounts are doing their job fine. But then it slowly starts to vibrate and quickly increases. So that says to me it could be one of two things. 1- someone else on here said maybe the mounts are just tuned poorly, and maybe the increasing vibration is caused by the idle naturally slowing down at a stop, and it's hitting just the right frequency to vibrate. ??? maybe. 2. Or it's something out of whack with the fuel mapping, and when I stop it just becomes more apparent. My fuel economy does suck even when I drive like my grandma. I've got a Scanner that gives me all kinds of Live data coming off the computer- including fuel mapping. But, it's just numbers to me! So yours is still doing this too?

It's been several months since my attempts to get rid of the annoying idle vibration. Here's the things I've done, in this order. 1 Cleaned IVAC, 2 Oil Change, 3 Air filter change, 4 Can of Seafoam, 5 Injectors professionally cleaned, 6 Transmission fluid and filter changed, 7 Had diagnosed at Lexus-again. Cleaned rear ABS sensors at their suggestion, 8 changed two engine mounts and one transmission mount, 9 Had exhaust system checked out at an exhaust specialist- they said my system was fine, 10 taken to two independent transmission shops- they say it is not being caused my the transmission or TC. I've tried about everything that's been suggested to me. This vibration is really annoying though, and I'm gonna try again to get rid of it. My license plate rattles against the body very loudly when it really starts vibrating. It's very 'un-lexus' to me. :) So. let me ask you guys this. Lexus had said the ABS system is causing this vibration. So, I only cleaned the rear sensors, and now I'm planning on doing the fronts. But, can the ABS system cause vibration while standing still? Anyone out there know this? If someone tells me that it can, then my next step will be to pop off the hubs and inspect the reluctor rings. And replace if any are broken. But I won't do this unless someone convinces me that ABS can cause vibration while standing still. Here's how it happens with my car. I will stop the vehicle at a light or stop sign, and it is smooth idle for 5-10 seconds, then it begins vibrating and slowly increases over a few seconds to it's full power- enough to vibrate license plates and antenna. If I turn the steering wheel a little bit, the engine will speed up slightly and smooth out. Or if lightly tap the gas it will smooth out fine. One of the transmission shop suggested to me it may be related the Variable Valve timing. ?? help me out lexus owners!

Lenore Why do you say not to use the Bosch plugs??? I put in the Bosch Fusions. I hope you don't know something I don't...