DeltaT

When my 2006 LX is cold (especially in the winter) there is a strange sound coming from behind the dash. It totally disappears when the vehicle heats up.
It sound a bit like a (dirty) electric fan. It seems that the pitch and volume changes when accelerating.
I have no idea what it is. Maybe you guys can help me out. I don't think it is related to the heater fan because it's not on when it's cold out and when it kicks in you can still hear the 'cricket's the background. So it's not freewheeling when the heater is off.

Chirp!

You can hear the chirping noise after about 1:20 minutes.

I took the nav screen and radio out, removed the blower motor, removed the interior filters and took a good look, but I still can't pinpoint the source. I even took it for a drive with all the stuff dangling and I could still not locate where the sound originates. There is simply nothing in the dash that could make that sound.
The only thing I can think of now is that it might be the AHC pump, which is located on the right hand side, just behind the dash. I replaced the AHC fluid a year ago. Could it be that the pump makes this sound when cold? And what can I do to solve it?

Bionoiz

No. AHC pump makes a different one. I guess its climite control blower

DencoLexus

I have almost the same thing but not as noticeable. I will be looking into it soon.

DeltaT

It's not the blower motor. I disconnected it and took it for a drive but the sound was there. O then disassembled it figuring that the outside wind might make turn, causing the sound. But even when I could see the parts not moving, the sound was still there.
I disassembled the centre console because I though the nav might have a little fan, but that didn't help.
It is strange that I can manipulate pitch and volume of the noise with increasing my speed and throttle position. It almost looks like it is vacuum operated. I even tried coasting with the gear in neutral and the engine idling, but the sound is still there. I even checked the front wheel bearings and the speedometer.

DeltaT

Please let me know what you find. I have been 'struggling' with this sound for more then a year now and still haven't found a solution.

gkar

Hi Delta,

Did you try to remove the CD changer - CD slot box?
mine made a similar noise during cold starts and noise stopped after stopping CD or removing the changer box. hope it helps!

HumanMale

Going to preface this by saying I have a 2007 LS460, but the sound from your recording is very similar to what I'm getting from my car.

A constant 'chirp' that comes and goes can be heard from the glovebox (where the A/C blower motor is housed), but only when the A/C is turned on. Sometimes, it's fine, but it never lasts for long that way. I find that sometimes running the A/C full blast for a few minutes helps get rid of the problem, but again- it always comes back.

I tried to upload the video/audio of my sound, but MP4s are apparently invalid files on Clublexus.

My mechanic (whom I just spoke with), said immediately when I spoke with him that it was probably the blower motor, but that it could be a belt as well. The way he said he could check was, the next time the noise came back, to open the hood and listen for the noise in the engine bay. If I hear it there, then it's likely a worn belt. If I can only hear it in the cabin, then it's a problem with the blower motor. He said he encounters it fairly often in the winter months when the A/C is blowing strong for long periods of time to heat up cabins.

I'm going to test tonight and then bring it in tomorrow for him to take a look.

As an aside, if anyone can tell me how to upload video to this forum (if possible), I would be more than willing to post what I have for you.

Here is a link to a post I began in the LS460 forum about my problem as well in case anyone's interested in exploring that: https://www.clublexus.com/forums/sho...d.php?t=769776

HumanMale

After having re-read your post it occurred to me that you might want to try the trick my mechanic suggested to me- if you can disconnect the blower motor, open the hood and then listen for the noise, you might be able to determine whether it's a worn belt IF you hear a similar noise coming from the engine compartment.

If it persists only in the cabin, then it's probably something else.

Just a thought.

DeltaT

Thanks for the suggestions. I will check the cd changer as well, haven't tried that yet. I will also check the DVD unit for the navigation (under the passenger seat). Maybe there is a fan in there that has dust buildup.

As for the blower motor, I am pretty sure that is not the problem. I have driven the vehicle without the blower motor (physically removed and disconnected) and the sound is still there. And I can't manipulate the sound by using the climate control functions. I am unable to reproduce the sound when the car is not moving so I won't be able to listen under the hood for the sound.

What baffles me most is that I can manipulate pitch and volume of the noise with increasing my speed and throttle position. It just doesn't make any sense.

As for uploading video's and sound clips, I use Dropbox. I upload a file to the 'Public' folder and just copy the 'Public link' in the message.

DeltaT

Well,I have tried it today without the cd changer cartridge and it make no difference.
As far as I can tell, the sound originates from the centre console area, where the transmission is.I seem to be able to manipulate the sound when I push the 4H/4L lever.

DeltaT

Okay. So my LX was in for service. And I asked them to check again for my noise problem.
They now suspect it to be the transfer case. But they are not sure what to do. Nor do I.

Any tips or suggestions are welcome.

DeltaT

Is there anybody that has an idea on how to proceed?
Can a transfer case be rebuilt? Should I consider replacing it? If so Where do I find one? Should I go for a used one or bite the bullet and price out a new one?

DeltaT

A lot of stuff has happened in the meantime but the latest news is that I've decided to sell the LX.
I have found a serious buyer, but I can't sell it with the whining sound. It just wouldn't be right.
So it's off to the transmission shop where they will diagnose and fix the problem.

I was cold this morning (-7F), so I made a new recording:

Transfer Case cold

I accelerate in the clip and end up doing about 55 mph. The sound fades away after 6 minutes or so. The crackling noise is the sound of cold leather and the phone rattling.

The second recording is when things are warmed up, also at 55 mph. As you can hear, it is nice and quiet:

Transfer Cas warm

I had them listen to the audio recording and they suspect the circulation pump (if the transfer case has one). I could be something simple as stuck debris or rubbing of parts which do not touch expanded due to heat.

They will be able to identify it once the T-case is cold so I left it behind and they pin point it on a hoist tomorrow morning.

Wish me luck.

suSharma

Dear Delta...sounds like you going nuts about it...dont take the whole mountain aprt just find there wsa a little mice in there...i drive mine with same sound for years...got used to it.

hankinid

"Dear Delta" hasn't been here since the post above yours today.