Da Hapa

Our RX has recenlty picked up the weird vibration at idle issue that I've seen posted about several times on this board. Essentially, there's a strange vibration in the car when I come to a stop in drive. The vibration completely disappears if I shift to Neutral or Park.

I've searched and found several threads on this topic but haven't been able to ascertain whether anyone has ever successfully diagnosed this issue and hopefully fixed it.

Can you help?

steevr

Only time that happens to me on my '02 is when the weather is really cold, even once the RX is fully warmed up. It happens only at idle in drive. Like you said, park or neutral is smooth. I also notice a resonating sound when it happens (almost as if the engine is groaning). The vibration I feel is in the steering wheel. It's been in the single digits here the last few days. That's when I've really noticed it. When it's in the 20's, it goes away once the engine warms up. 30's and above, I never seem to notice it.

Hope that helps.

santorini

I, too, have noticed the rough idle when the RX is in drive. It happens primarily when I'm stopped at a light. I've noticed a slight vibration in the steering wheel, with a more pronounced vibe in the driver's door...

I've only had my RX for about 2 months, so I'm still getting used to it, but this seems odd.

I've scheduled a service appointment for next week for this issue & my squeaky shocks.


BTW, Da Hapa, did you/do you have an S2000? I thought I recognized your name from another forum. I still have mine '00 with only 19K!

Da Hapa

Let me know what your dealership comes up with on the vibration, will you?

Yes, that is me. I had an 01 silverstone and red for a year and 15K miles. I sold it for an spa yellow pearl 02 that I put about 10K miles on before I sold it. I made the difficult decision to sell that car a few months ago when my Dad suffered a debilitating stroke and the money I had tied up in that toy (it was our weekend/date car) was better spent helping my folks out. Someday, I might replace it, although I'm not a big fan of the supposedly "updated" 2.2L S2000.

ederny

I've had the virbration in cold weather when comming to a stop as described. I've chalked this up to low rpm under load (in drive). The vibration is a normal side effect of only having 6 cylinders, a 4 banger is even worse at low rpm.

So, my question would be is the rpm abnormally low when coming to a stop from run speed? I'll have to take a closer look at this and see if the rpm is really lower than expected or if this is something else.

bizzy928

We took ours to the dealership for the exact same problem.

The foreman told us it was totally normal. It was the resonators and the idle tone. They were supossed to fix it in the rx330 because of all the complaints but Lexus didn't and the "revision" was even worse. Its also winter here, so the temperatures are always below 0 degrees celcius.

Da Hapa

Hi Ed -

I certainly understand the physics of what you're describing and agree that apples to apples, a V6 is more likely to have this problem than an I6 or I4 but...

In this case, my RX300 never had this issue until recently. Its been in the family since new and while it was in N. CA and is now in S. CA the climate change isn't that drastic.

It still seems odd to me.

ederny

Da Hapa,

Sure, I see your pouint of view. I also have some doubts because I would not exactly expect rough idle when coming to a stop after driving (all warmed up and everything). I would bet there is a slight stretch that Lexus made in programming the chip for the engine at idle that puts it in a rather lean condition at hot idle to save on fuel efficiency and pollution. So, we are seeing it under the condition of hot idle. If we could just tweak the mixture curve a bit....

Then again, it could be something simple like changing warn plugs. I'll be watching this for any improvement with future maintenance.


oh well !

santorini

I took my RX to the dealer yesterday & went for a drive with the service diagnostics manager. I pointed out the heavy idle/vibration problem to him & he acknowledged that it is a common problem with RX300s. He also said they had hoped the problem would be fixed with the introduction of the 330s but it was not.

He said Lexus has identified a fix for the 330s & will "unveil" this fix within the next 2 weeks. He said they're rather secretive about the details, but it involves changing or adjusting the mounts, or something to that effect. Evidently, the mounts are different in the 300s vs 330s.

Anyway, for my RX, they cleaned the throttle plate. It was slightly carboned. It did seem to help the problem, but it didn't make it go away...

I'll be back in touch with this guy in a month or two after they've had an opportunity to "test" the fix on some 330s.

I got A LOT more info from this guy vs my service advisor. The service advisor told me the heavy idle/vibe "wasn't a common problem". Yeah, right.

BTW, the noise that I thought was squeaky shocks was actually my sway bar bushings. They needed to be replaced.

Da Hapa

thanks for the update.

let us know how you progress.

mooretorque

I think part of the problem also has to do with A/C compressor cycling on and off without a programmed change in idle to speed to compensate for the increased load, thereby causing rpm to drop by a couple hundred and making the imbalance more apparent. Again, as ederny points out, worse with an I4, too.

This was actually apparent on our RX300 from day 1, but since it was apparent that it was occuring with compressor cycling (and was certainly something I was used to from my old Honda Prelude days), I've never been concerned. Evidently, despite AUTO temp control, in the RX the compressor isn't always on.

(To some degree, Lexus has addressed this in other models; my GS idles about 200 rpm higher when the weather is warm enough that the AUTO function keeps the A/C compressor on; when OAT drops below 29 F. according to my display, my A/C shuts off and idle speed (both in gear and in neutral) drops.)

p1fcl01

I too had this problem for few years already. My mechanic had told me that this was due to the Engine Mount worn out. This is a very common problem with the 99-00 RX300. I did not change this because it cost
$800 to have this fix. I'm in the market for a new car anyway, so I've left it for now. As to the post that said this was a problem and will be fix on the RX330, what about the RX300 that had the same problem!!! That's why I'm now staying away from Lexus, don't get me wrong, they're great cars. It's just that I think Toyota is no long ther Toyota they used to be. Just my 2 cents. Hope this helps.

chikoo

Has anyone changed the engine mount and got rid of the idle problem?

My other car is a 2003 Mazda6 and it is smoother at idle than my 01 Lexus RX300.

The resonating booming sound at idle coupled with the vibration is a deal breaker for me and I end up driving my Mazda6 more than the RX300.

I would certainly like to know if replacing the engine mount solves the issue. If it does, then I will get it done.

Lexmex

Last year when I went to Toyota to do an alignment (I go there periodically to show off my latest mods), they swore the engine mount was going dead after looking at it. This year, I sometimes notice what you describe and sometimes I do not. I was also told by both Toyota and my uncle (who is an absolutely perfect Mexican mechanic) that if the engine mount is going really bad, you will hear a much worse sound than just a vibration.

HarrierAWD

No vibration on my 2002 RX300 with 59K miles. Try downgrading to regular gasoline. Premium gasoline with too much octane might mess up the engine timing.