ancdmd

2002 UL with 132k miles, all service up to date, including new AC compressor, alternator, serpentine belt, idler pulley, all new suspension components. Amsoil full transmission flush not long ago. These three noises continue to be undiagnosed by techs. The first has been going on for 9 months, happens with throttle barely touched by my foot and at highway speeds, it's a terrible ringing sound. I had the heat shields removed from the y-pipe so that an be ruled out. Never thrown a code and no stored codes either. Numerous techs have looked at it and can't find anything:


The next two noises started simultaneously about ten days ago. Here in Miami beach we had some high tides and I drove through some fairly deep salt water several times. I'm not sure if this caused the problem. I have a high-pitched whine that is vehicle speed related and starts above 20 mph:


The last noise is too faint and low-pitched to be recorded, it is a gear-grinding noise or chatter that sounds like it is coming from under the shifter area, it is only audible at very low speeds when coming to a stop. It sounds exactly like the teeth of two gears meshing together, and as I come to a stop you can easily hear the chatter slow to a stop also. It's definitely due to something rotating. Again a tech checked it out at LX Auto in Kendall and they couldn't find the problem, everything under the car appeared fine.

LionsGate

Take a look at this link, read the first post and the last.

http://forums.nicoclub.com/ringing-e...e-t385835.html

BTW, Google indicates all sorts of cars/people experiencing this odd ringing issue.

As to your other noises that might be related to driving through water...could debris, sand, grit, etc. have washed into some component(s) and now you're experiencing rubbing/rotational sounds?

Boomer01

I have the similar noise in the first video. Still haven't pinpointed it.

https://www.clublexus.com/forums/ls4...gas-pedal.html

ancdmd

It's quite possible the salt water has something to do with it, but it just doesn't make sense that the techs wouldn't be able to figure it out. Honestly its a Florida car so one brief exposure to salt shouldn't cause a problem, especially compared to the amount of salt cars see up north. I'm trying to analyze all the moving parts in the driveline to see what could be making the noises, and all the obvious wearable items like mounts and the center driveshaft bearing are all ok. Techs said the transmission is fine. I've never heard of an exhaust issue like in that thread, and I'm not suspecting it either because my car's symptoms are quite different than the Infiniti's.

Thanks for the help!

ancdmd

The low-pitched, rumbling, gear-grinding/chatter noise is actually audible during normal driving too, it sounds as if a small idling diesel engine out of an 18-wheeler is sitting in the console LOL

SC400slide

iTrader: (11)

First noise sounds sorta like metal vibrating, it might be a warped rotor scraping intermittently with the brakes low.....wild guess! Second noise might be wheel bearings, another wild guess ...(in clip 2, who saw the Lexus RX??) Clip 3 might be missing rubber between the 3rd member...

yuri.ber

iTrader: (7)

The third, speed related noise might be a loose/perished door seal.
I have the same thing, only strictly from 35 to 40mph. Didn't look in to it yet though since its only audible when radio is off.
Dash noise. Did you check your cabin air filter in the glove box? Maybe it needs to be reseated. You can try to disassemble the whole center stack and add some insulation and carefully put it back together.

Rattling noise. Clueless for now. I would've said heat shields but you removed them already. A! Maybe a piece inside one of the cat converters broke off and clunking?

ancdmd

I ordered new motor mounts. I had replaced the transmission mount 9 months ago. I had the last tech look at the motor mounts and he said they had some wear but nothing major. At 132k miles I'll assume they're close to the end of their life span anyway. Bad motor mounts can cause a slew of odd noises so I'll give it a shot, if it doesn't fix the problem at least I'll be able to rule out the mounts..

ancdmd

Air filter is ok. When cats fall apart they make a thud sound, lots a videos on YouTube about that, plus never thrown a code either.

ancdmd

Brakes are all fairly new, including rotors. Tech ruled out wheel bearing last week. Trans mount is new.

ancdmd

The noise in the first video has been eliminated today, I had the motor mounts replaced and the noise is now gone. I don't know if it was the actual mount(s) that was making the noise or something else rattling because of the mount, but either way it's gone. Both mounts were broken.

The second whiny noise is still there, I'm convinced its the driveshaft center support bearing. I'll have it replaced and see if that does it.

Viper6

You say Amsoil trans flush? Does your vehicle not require the Lexus WS fluid, or is that only 04 onward? I would check fluid level and confirm proper fill and not undefilled with exposed gearing noise eminating like that...

ancdmd

Yes Amsoil, '02 takes Type IV fluid I believe... The Amsoil synthetic ATF is fully compatible. It's not under filled.

ancdmd

I replaced the driveshaft center support bearing today and my car is now noise-free. After I replaced the motor mounts, the noise in the first video went away, so I thought... but after a couple weeks I could still detect it somewhat. Well today it is gone, apparently that bearing was making both the ringing noise and the loud hissing noise. I don't know if the failed motor mounts caused the bearing to go bad by somehow changing the geometry of the driveline and stressing the bearing.