Hello experts,
my 2000 RX300 has a constant noise from behind the center console. The noise happens when the key is turned to ON position, no need to start the engine. I recorded and attached the youtube link here, hoping someone knows what causes the noise and how to fix it. It sounds like the disks are being loaded but it is not; I took out the disk cartridge and verified it. It's not the air directing servo either as I fixed the servo a few days ago, also the servo noise is much different and much louder.


It's annoying but it does not affect anything in driving.

Thank you for any hint.

 

Please search on Mode servo. You should find plenty to read and instructions to fix.

Salim

 

Thanks for the quick reply. So it is still the mode servo? I just fix the servo a few days ago and the loud annoying noise is gone. I will take the servo module out to see if this noise still occurs. If I remember correctly, this noise occurs regardless the mode setting, to face, to face and feet, to feet and windshield, etc.

 

It is the "Auto" setting that keeps or tries to keep changing the air flow pattern. If you take it out of the "Auto" and control it with mode button then the servo will struggle to get into one position and then quit attempting.

Some servos loose power and can not actually change the flow pattern and others (can be the motor or the links) just have lost the lube and you hear the rattling noise.

Salim

 

You know there is a mix servo too right?

 

SVRX300,

If you swapped the mode servo, you should be familiar with the location of the air mix servo. Take out the glove compartment and watch the servos with the A/C running and see which one is making noise. The mix servo makes a noise described like a gerbil running on a wheel as it hunts for the correct position, but can't due to the grease inside the servo getting contaminated with wear particles from the carbon contact surfaces. You can open the servo and clean the grease to solver the problem, or just install a new servo.

Here is a thread that shows info on cleaning the air mix servo
https://www.clublexus.com/forums/gs-...omotors-4.html

 

Hi Lexmus, I watched the youtube in the link you provided. That is the servo I fixed a few days ago. Before the fix, the loud rattle only disappeared if I set the mode to "face and feet", regardless A/C is on or off. I took the servo module out, pried out a little the worm gear on the motor shaft such that its axial play is very minimal. Put it back and the rattle is gone completely. I test it under all conditions, all modes, low and full fan speed, etc.

The noise I mentioned here is a different one. It is much low level, a little similar to the noise when I pop in the 6-disk cartridge in and something is sorting/counting 6 disks. When I drive I can barely hear it with the road noise present.

 

eject the cd cartridge.

Salim

 

I took the cartridge out as the first step. It is not the cartridge.

 

How about assuming the astronaut position, touch varies parts till you can feel the part that is vibrating.

Salim

 

So is the noise always there even if the radio and A/C is off?
Did you look into the cassette player to see if it is running and making a noise?
Is your cabin air filter present? It almost sounds like something got past the filter and is rattling around behind the vents.
Open the hood and see if the noise might be coming from there.
If it is related to the A/C, I would remove the glove compartment to help debug the noise.

 

This noise is always there with radio and AC off. Key needs to be turned to ON to hear it. No such noise when key is turned to ACC. Strange enough, I just checked it now and the noise only lasted a few seconds then gone. I will do some more debugging tomorrow. I also checked that there is no tape in the player
Thank you all.