Idle Vibration

[bluestu]

Has anyone had a problem with a low frequency vibration when sitting idle at a stop? It goes away when I shift to neutral or park. As soon as I put it in gear, the idle drops down slightly and the low frequency vibration resumes. It seems to be coming from the rear of the vehicle. Any opinions as to what might be causing this annoyance?

[Rx330driver]

Has anyone had a problem with a low frequency vibration when sitting idle at a stop? It goes away when I shift to neutral or park. As soon as I put it in gear, the idle drops down slightly and the low frequency vibration resumes. It seems to be coming from the rear of the vehicle. Any opinions as to what might be causing this annoyance?

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If its a slight vibration, i think this is normal as the engine is worn from use. At stoplights, i usually put it in neutral just to stop it.mostly engine wear i think.

[bluestu]

The engine runs great!!! The car shouldn't vibrate like that unless there is some sort of design problem that I'm not aware of. Anymore info. would be greatly appreciated. thanks.

[Rx330driver]

how much of a vibration are we talking about. Mine is enough so u can feel it on the steering wheel as well as your body. But usually when the car warms up, the vibration dies down a bit. obviously it if was like massaging vibration that would be a problem. :whistles:

[LexKid630]

It is 100% normal (well that's how they're supposed to be). I've owned 3 rx300's and they all did it. Even when new. It's worse when the A/C or heat is on.

It's a known agrivation.

[bluestu]

It is 100% normal (well that's how they're supposed to be). I've owned 3 rx300's and they all did it. Even when new. It's worse when the A/C or heat is on.

It's a known agrivation.

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Thanks for the info.. I guess I'll have to live with it, although it is my wife's RX300 that the problem is more noticeable. Too bad for her. Ha ha.

[chiks]

Normal? are you crazy?

a $15000 price Mazda/Honda idles better.

Are you sure that there is not a problem with the IACV - Idle Air Contrl Valve?

I have the same problem where after the car has warmed up thoroughly, idle would drop way low when coming to a stop at a stop sign. Ath this time, the gear selector is in "D".

The low frequency vibration is enough to make me mad as it drones throughout the passenger cabin and gives me a massage like vibration.

The first dealer I showed it reported it as Normal!!!

I now have the Lexus District Rep invloved and let us see where it goes.

[RX in NC]

Be sure to check the condition of your engine mounts. Shaky idling can be the first noticeable symptom of the rubber components in your engine mounts beginning to break down and wear out.

[mh6]

I have the same problem and it drives me nuts ......I am going to start chasing it down on how to improve it.

I will find a way to isolate it better.

[chiks]

in any case this is not normal.

I have driven quite a few RX300s that do not have this problem and with more miles than mine.

In fact, Lexus press releases in 1999-2000 boasts about the Active engine mount that literally emiminates any idle vibration. How about that?

http://www.autoworld.com/RX300.htm

http://www.theautochannel.com/vehicles/new...0/solo0024.html

[RX in NC]

Again, check your engine mounts. On any vehicle that has passed five or six years in age, the rubber components in the engine mounts can begin to break down. Particularly if any oil, transmission fluid, or other liquids have been spilled on them over the years.

[chiks]

Certainly. your point is well taken.

however, like I described earlier, the fact when I experience this vibration, I observed that the RPM is dropping down and not staying very stable (slight flutter) and when the AC kicks on, the speed goes up and there is lesser vibration. As soon as the AC is disengaged, the idle speed drops down and the dreaded vibration is experienced.

doen't sound like the mounts are the prime culprits.

[tta300]

I've recently replaced the torque rod and front engine mount on my '99 rx300 (94,000 miles). The idle vibration problem has improved a lot. It was a 2-hour DIY job without any special tools. The front engine mount is fluid filled and vacuum controlled. It tends to fail over time.

[chiks]

what is a torque rod?

[tta300]

what is a torque rod?

On the top passenger side of the engine, there is a rod (dog bone) that links the engine to the body. The rubber insert on both ends gets hardened over time. You'll find some discussion of the subject, if you do a search here.

[chiks]

Here is the latest run down of when the vibration occurs:

1. Vehicle is throughly warmed up

2. Light switch is on Auto or Off

3. Gear selector is in D

4. Foot on the brake pedal

5. AC is switched off

At this time, the idle will drop to maybe 600 and the vibrations and the ensuing drone in passenger cabin is unbearable.

Now look at the changes in some of the variables and how it affects the scenario:

#1:

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If I switch on the lights (not on auto), the idle speed goes up to ~750 and once again idle vibration is there, but minimal.

#2:

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If I take the foot of the brake pedal and instead use the e-brake, idle speed goes up a bit, ~700-750 and the vibration is there, but minimal.

Now what do you think is the probable cause?

In my opinion, the mounts are certainly worn as I can feel some vibrations in any case.

But the dropping of the idle speed and the resulting increase in vibration is of concern here.

[Rx330driver]

lol!! how can turning the headlight switch to auto help, or make the ide worse. that does not making any sense to me

[mehullica]

With the additional load from the alternator the idle speed will change, most people won't notice it. Does the Rx300 have a tow hitch? I have seen a couple muffler mounts sag on tow hitch. This caused the exhaust system vibrations to resonate into the body.

[bluestu]

If you put the car in neutral, the vibration totally disappears. The vibration seems to be eminating from underneath the vehicle.

[chiks]

the fact of the matter is that the idle speed should not change that dramatically. The RX300 is not the only v-6 vehicle I have. I also have a Mazda6 V6 that idles so smooth that you would think the engine is switched off. I also had a 4 cylinder 100hp car that exhibited idle speed fluctuation when I switched on the rear window defroster. The RX300 is not a cheapo 4-cylinder, nor a cheapo hyundai. It is a 220hp V6 made by Lexus/Toyota. This is unacceptable and I am sure this is due to a fault in the electrical system somewhere.

[lexuschuck]

Has anyone had a problem with a low frequency vibration when sitting idle at a stop? It goes away when I shift to neutral or park. As soon as I put it in gear, the idle drops down slightly and the low frequency vibration resumes. It seems to be coming from the rear of the vehicle. Any opinions as to what might be causing this annoyance?

O.K. I might get in some trouble here but here are my thoughts....I have a 2001 RX300. I have felt the vibration and noticed it on all of the RX300's I test drove. However, I also noticed it goes away when the engine gets to operating temperature (normal in my mind). If the air conditioner is on I can notice it a little more. However, no matter how you slice it, this is an SUV not a car. I have never been in an SUV without some vibration or engine noise. Thus although some may find this unacceptable for a $40,000 vehichle, it is what it is (an SUV/truck) and deserves to be reviewed as such with the same expcetations. Maybe mine is not as bad as others but to me this is acceptable.

The one thing this forum has taught me is that people expect their Lexus to do the following: Never break no matter how hard they drive them and/or how little they maintain them, make zero noise from the engine or rattles (impossible), and blame Lexus for making a high priced inferior product if anything like this occurrs (unfare). Now I agree the transmisson issue is a concern but the one thing I would like to know on the transmission end of things is of all of the people aho have had this trouble, how many have had this issue on a vehichle they have owned since day one? How many failures from people who have bought their 300 used and have no idea how it was driven by the prevous owner?

[bluestu]

That seems like a reasonable explanation to me. I wonder if the 2WD version has the same vibration? Like I said before, mine only vibrates when it is in gear at a stop. Put it in neutral and the vibration totally disappears. It definitely has something to do with the engagement of the AWD transmission. My old 4WD Isuzu Rodeo vibrated a lot when I engaged the 4WD. One thing I can say for sure is that the RX300 is a vastly superior car compared to the Isuzu Rodeo.

[tmastres]

I have to agree with you somewhat Chuck, a Lexus is just a car and its not like they're hand made. Nonetheless I think Its most likely the result of a wear Item like the aforementioned engine mounts or the like. My 2000 RX is now 6 years old and thats a lot of time out of doors, its likey those types of things wil wear out. At least thats where I'm going to attack this problem from.

[stonecutter]

lexuschuck, I don't think you can call the RX an SUV, it is not truck based, it is car based. At best, we can call it a crossover. People expect the RX to drive (and ride) like a car because that's how Lexus want people to think of it as, a car that has the "roomyness" of an SUV, in fact, didn't they market it as an "LUV" ? The utililty comes from the loading space and hatchback convenience, not from the ability to go offroad. So the RX should be judged with the same standard as that would applied to a car, a luxury car at that. My '05 idles with no sound and no vibration whatsoever, and I expect no less.

You are right that sometimes people expect too much and !Removed! about every little thing on this board, but a quiet and vibration-free idle should be standard fare on these vehicles.

[chiks]

Has anyone had a problem with a low frequency vibration when sitting idle at a stop? It goes away when I shift to neutral or park. As soon as I put it in gear, the idle drops down slightly and the low frequency vibration resumes. It seems to be coming from the rear of the vehicle. Any opinions as to what might be causing this annoyance?

O.K. I might get in some trouble here but here are my thoughts....I have a 2001 RX300. I have felt the vibration and noticed it on all of the RX300's I test drove. However, I also noticed it goes away when the engine gets to operating temperature (normal in my mind). ....

If this was the case, I can accept it. It is understandable to have some vibrations when the engine is still cold.

However, the opposite is the case in my 01 RX300. The vibration at idle is felt AFTER the engine has warmed up thoroughly.!!!!!!