tjh1992

Hey guys, new to Club Lexus. Have an 2003 RX with 253k on it. I'm currently dealing with a mystery of a noise, thus my need for this forum, as I'm generally savvy enough to fix stuff on my own time. The noise is a whining/howling sound in which increases in pitch with speed, and decreases in pitch with coasting. It happens between 48-52 MPH and again, happens upon accelerating and deceleration. It is a noise only at that speed, so it's not a matter of RPM. Here's the tricky part. I noticed this noise last year in the cold of these MN winters and assumed it was my roof rack catching a weird wind draft or something. Once spring/summer came, the noise went away and never came back once. However, fall came around this year and as the temperatures dropped, the sound came back again. No louder, no quieter, just the same as the previous year. Here's the trickier part. The sound goes away after a long drive (5 hours was the drive I noticed it stopped happening), but still happens once the car is "warmed up" within 15-20 minutes.

The transmission was rebuilt at 187k, so I've ruled that out. Would love any other thoughts you pro's have!

trhs75

Well, it looks like you've considered the roof rack, which would have been my first suggestion. Just for curiosity's sake, maybe mark where the two roof racks are on the track, then move them somewhere completely different (or take them off?) and see if the noise disappears or changes. I would also try sometime when the speed is just right and you're hearing the noise, shift into neutral and hear if the noise abates. I don't suppose it would be wise to shift back into drive at speed, so maybe just brake to a stop in neutral. My money's on the roof racks. Air has a different density at different temps, so maybe the temperature change is enough to change the sound.

LSBen

Sounds like wheel bearings to me. Listen if the sound is coming from the front or back wheels and replace them in pairs

maxSteel

Could be wind noise that happens when a door or window gasket is cold and stiff.
That would explain why it doesn't happen in warm weather.

tjh1992

I replaced the rears back in August, not because of that sound but because of the obvious wheel bearing sound it was making in the back. The whining noise I'm dealing with now is coming from the front, but it's a completely different noise than the noise I heard with the rear bearings. Would those bearings sound the same when close to replacing?

tjh1992

Took the roof rack off completely, and the noise was still there. I shifted down into neutral when the sound was happening, and nothing changed. Not sure if that's a good thing or not...

trhs75

I'm certainly no expert, but after ruling those out I'm inclined to suspect a wheel bearing or axle. Shoot -- I was hoping the roof rack would be the culprit. To test maxSteel's suggestion, could you have a passenger unlatch one door at a time as you drive, hoping the wind noise wouldn't drown out the noise you already have?

2KHarrier

Are you sure it's not the transfer case making noise at those speeds? Assuming it's AWD, that is.. My RX would whine when it was cold outside (below 20 F) and would continue to do it well after the vehicle was warmed up, but eventually would stop on a long drive. If the temps got closer to 32, then it wouldn't make any noise at all.

sktn77a

iTrader: (2)

Tire noise?

tjh1992

Been through two sets, still noise :/ That was my very first assumption.

tjh1992

That's what I'm afraid it is now. I went ahead and took it in to my mechanic and they're pretty sure that's the issue. Obviously a pricy job. I was surprised to hear that however, I thought transfer case issues were more of a grinding sound. Did you end up fixing yours? Worst case scenario I don't get power to the back tires, right?

tjh1992

Thanks for the suggestion. Tried opening the doors and still nothing. Had my mechanic think the issue is T case

trhs75

It's certainly inexpensive and fairly easy to change the transfer case and differential fluids, and it wouldn't hurt anything to change them. Any chance that would reduce the noise? I didn't ask if you'd checked the levels.