dgdembeck

65 Y/O Retired Lexus owner. 2004 LS 430 has a humming sound coming from rear of vehicle. My long time mechanic changed all 4 tires, replaced the R/R hub assembly, brakes all around, and finally had the rear end grease changed to synthetic....IT IS STILL HUMMING???? He is frustrated, I am out $2500, and the damn sound is still there???? I am begging for some help. Just turned 100K, and the car is beautiful, still. If u might have a suggestion, email me at dgdembeck@yahoo.com. Sincerely, Daryl

DaveGS4

iTrader: (2)

does it only hum when you are moving or also at a standstill?

Can you better isolate where the sound is coming from?

dgdembeck

TY for the quick reply....It is only when on the road.....The highway drive is louder than on the normal roads. When I let of the gas, it gets quieter. But when the car is moving, it hums.

dgdembeck

TY for the quick reply....It is only when on the road.....The highway drive is louder than on the normal roads. When I let of the gas, it gets quieter. But when the car is moving, it hums. It is coming from the back of car. My mechaniic put new tires, brakes, and R?R hub assembly on in the last month, and Friday he changed the diff fluid. Not quite as loud, but it is still there. Only 100K on the care, and it is still a beaty

DaveGS4

iTrader: (2)

Hmm, given everything else you've done, wonder if it could be the fuel pump.

Think on the LS (like most sedans) it's under the back seat and when it goes bad it often makes noise

jimbosr1

check your transmission mount.When it is worn you will have a drone sound ,they are cheap to replace if you don't work on you own car.My money is on this mount.

Bocatrip

tallcaguy

Good suggest. However, if it's worn enough to cause a drone at speed, wouldn't there also be some vibration at idle in steering wheel and/or shift lever? My LS has 112. Just replaced my trans mount because of those symptoms. The mount def looked worn.

tallcaguy

Some 04's have a barely noticeable high pitch whine at 70-80. It gets quieter when slowing down. Sounds like your problem is a lot worse. Agree Bocatrip that the L/R axle assembly might be worth checking. Did the problem just appear suddenly or has it been slowly getting louder?

dgdembeck

Brother, you have been driving my car. It started about 2 months ago, at least it is when I noticed it. Barely hear it when on normal streets. As I get to 45 and above it is more noticeable. At highway speed, it is loudest. It is a constant hum and I will try the back seat test to attempt to locate....Left/right/middle......Just spoke to my mechanic, and he is afraid to keep taking my money????Bless him, although I am thinking the same thing, LOLOL.

Johnhav430

Not to state anything obvious, what kind of tires are you running, now that they have been changed?

I had gotten my car in Oct. '16, and in < 30 days slapped snow tires on (so I did not know the car well at this point). They whined all the time, totally speed dependent, and I convinced myself through my research that I had a driveline issue, likely the rear end, possibly carrier bearing. Spring came and when the all seasons went back on I said huh? No sound?

dgdembeck

Live in Fla.....Top of line Coopers, all season. Replaced a month ago to remove from checklist. Still humming. Thanks, seems like we have the same checks and balances.

2KHarrier

Does the sound change pitch, or just volume with the various speeds? I too am suspect of the Left Hub Bearing assy.

dgdembeck

MMMM.....Actually both. When coming off Expressway, the hum changes pitch and the noise level reduces. When at street speed, it is there but almost negligible. Above 45 to expressway speeds, it is certainly there.

Johnhav430

Is it even possible that it could be a transmission whine? I don't know if anyone here has ever complained about that....on my car, again when I had it < 4 mos., an indie did my LCA bushings, and then their own multipoint...and reported that my rear output shaft was leaking. They suggested addressing it, since my car has no dipstick. I'm thinking that with no dipstick, we really do not know what the level is, so if it leaked out but not enough for us to notice on the ground, it's possible the level could drop? When I saw my car on the lift, I admit it was not a lot, and I'm glad the tech found it...

p.s. two Lexus dealer multipoints did not spot it, so it could realistically not be noticed...