lirtz

My 2005 RX330 has run fine for all 45000 miles to date. One exception is that there is a high pitched hum that becomes noticeable once the car reaches 30 mph and continues to increase pitch until about 45mph. The hum seems to disappear when going faster than 45. If you cruise on a quiet street at 30mph the hum will stay steady if you maintain speed. The hum will increase if you accelerate. But... if you take your foot off the gas pedal the hum instantly stops. Put your foot back on the pedal and it instantly starts. You can almost "play a song" by taking your foot off and on the pedal.
Lexus service clearly heard the sound during a test drive, but could not figure it out. Any ideas or suggestions out there?

Rainbird

Welcome to Club Lexus Lirtz. I have a similar sound (droning ) that starts at 70mph plus. The sound instantly stops when you take foot off accelerator and starts again with foot back on pedal. That fact seems to rule out a wheel bearing. I had Lexus evaluate it when I had some service done. They couldn't duplicate the problem because their techs are not allowed to drive over the speed limit (65mph). I think they didn't have a clue or just didn't want to deal with it. Sorry I can't help, but if I find out what it is I will post back on this thread.

HtownBlue

A few things I would Check:
Is it coming from the stereo (ground feedack)
Can you duplicate the noise with the car in neutral but with the RPM's around 2000 or 2500?

If you turn the wheel while the whine is presetn does it effect the pitch?

At the speed of the whine, keep your foot on the accelerator but shift to neutral and see if the whine goes away. If so, it is drive train related IE: it makes the noise when the tranny is engaged or acles are turning.

Do you have AWD or FWD?

It is possible the noise is wheel bearing related, so don't rule it out.

Check your brake dust shield.

See if your emergency brake assembly is operating correctly and not staying engaged.

Check your belts and make sure they are tight enough.

Try turning off the a/c and see if that effects the noise.

Do these and answer back please.

Rainbird

HtownBlue - Thanks for the suggestions, I think one of those will be the answer. I made a copy and put it in the RX350. Mine is a FWD model. Now to find a smooth stretch highway to try these suggestions on. If you have been to California lately you know that is a serious challenge

HtownBlue

HA! I live in Houston and I understand the lack of open roads. I have to drive about 50 miles to find a country road sometimes.

Try the above suggestions. See if you can isolate any related causes/effects for the noise. See if it is Engine RPM related, motion related, tranny related, maybe even audio related, or even bearing related (turning wheel during sound), also apply the brakes during the sound a little and see if that effects the noise, etc. etc.

Post what you find and we will try to trouble shoot it for you little by little.

zig

Hello, I have a rx350 2007 awd and i have the same noise as yours, do you solved your problem?

2004lexrx

I know this is an old thread but did you or anyone find out the root cause and how to fix the humming noise which was mentioned by the original poster?

rlee777

I am the proud owner of a new (to me) 2004 RX330 AWD and I have this exact same issue. Has anyone resolved this? Any resolution would be greatly appreciated.

Pullhook

AWD RX350 and I have a similar hum, seems to come from the front but I've been fooled before, the mystery is only at a particular speed around 55mph, faster or slower and the hum goes away. Low pitched, I wouldn't call it a whine like you get from worn gears and it only appeared recently, I thought it might be tire related but can't say for sure, I used to own a truck with all-terrain tires that hummed on the highway but that increased in pitch according to speed.
Just speculating but the fact it only appears at a particular speed suggests it could be wind related making something like a plastic cover vibrate at a certain frequency. .

rlee777

What makes this whine unique is the direct relation with the accelerator pedal -- once I let up on the accelerator, the hum instantly goes away. Comes back when I press the accelerator. Does seem to peak in the range of 1500 - 2500 rpm. This drone can be very noticeable at times -- what I am noticing now is that this seems to be subsiding as the weather in my area is warming up.

rlee777

Update: this humming is coming from the transfer case (AWD).
https://www.clublexus.com/forums/rx-...ion-whine.html

I took out the fill plug (drain plug was stripped so someone in the past was here) and pumped out only a few ounces of dirty fluid. Refilled with Valvoline Syn 75W-90 and the noise has reduced quite a bit. Not leaking gear oil that I can see, so I am not sure where the transfer case is leaking. In any case, I can keep the fluid level topped off for the remaining life of the vehicle.

Oro

This has reduced/relieved whining t-cases and diffs for some people. I use it though not for that purpose. Cheap enough to give it a shot + other benefits. Same price at NAPA if you don’t have Prime.