Ok, here's the scoop:
Just found an 11 Long with 138k miles. Perfect condition. I notice, though seems no one else really does, that there is a hum which I feel like is coming from the passenger front wheel. The interesting thing is that it goes for (say at 40 mph) about 2 seconds, then 2 seconds gone, then back for 2....over and over. Almost like if you were on the edge of the interstate hitting those sway cuts.

It is not loud or rough, but a lower pitched hum which I feel like I can feel a tad in the gas petal.

So...is it a wheel bearing? An oddly worn tire? Something else all together? A wheel bearing would be more of a constant sound, correct?

I am the type that now that I know about it, it's all I think about when in the car! ha!

Another thing-I have swerved in the road and did not see much variation. FYI- I did make sure to turn off the AC and fans and seat coolers to make sure it wasn't something else running.

Thanks so much!
Justin

 

Does it have air suspension? If so, it could the pump coming on indicating, there is a leak somewhere.

 

Try rotating the tires and seeing if it moves around, a bearing is usually constant and will change when you load the wheels

 

No sir- no air suspension.

 

Gas pedal is electric, fly by wire. You won't get that feedback "feel" like an old tech mechanical throttle. Like Striker suggests, rotate tires. It could easily be that one tire. Keep us posted.

 

Check wheel bearing (lift FW then rotate wheel manually and lesson closely) . It's difficult to isolate the humming sound while driving as noise reverberations changes based on surrounding. Best to stop by a tire shop and ask them to validate origin of the noise. If it's the wheel bearing, better to do both sides. Good quality replacement part from
and

 

If it’s a wheel bearing usually you can isolate it while driving by placing it under load.

Example — Drive straight at 40 mph, turn the wheel slightly to the left...if it repeats the hum, it’s the RIGHT WHEEL BEARING.
Turn the wheel to the RIGHT, if it repeats the hum, it’s the LEFT WHEEL BEARING.

If it does neither? I’d check the tires. Tire cupping wheel mimic wheel bearing noise. Google tire cupping. And if the tires are cupped I’d be worried that the struts are leaking/worn, and can no longer control the spring (tire is bouncing slightly while it’s driving over bumps = tire cupping = wheel bearing type sounds). Good luck.

 

no word on this issue from Original poster since the 20th of June.

 

Mine does that sometimes when i first drive away then it goes away, Nothing to worry about

 

Hmm, I'm a bit late on this.

with my experience, wheel bearings. Wheel bearings take a heck of a beating more then what we think. They wear quicker on rougher roads 07-09 LS. Don't know if they changed wheel bearing design on the 2013+ models.

Changed both of my front wheel bearings at 150xxx miles
The rears havent been touched but im expecting them to start whining in about 40xxx miles. My 09 LS currently has 258xxx miles.

 

Yeah, unfortunately not. We have had three places check. All agree not the bearings. Almost seems from driveshaft. Dealer looking at it Thurs! Doubt I will have it done there but maybe they can trace it. The other place even took a stethoscope and couldn't find the exact spot. Wild!

 

@lexus13dan, then apparently not the same. Mine does not ever go away.

 

If different people are hearing the noise from different areas then it's most likely harmonics, under your car you can see dampers in a few places to help with this.
NVH can be difficult to pinpoint and takes time...Dealers used to use the Midtronic scan tool for this but it usually ended up pointing to the tires so it was kinda useless, I imagine they use techstream now.
If you're the only person hearing it I wouldn't throw any money at it until it got worse.

 

There have been several recent posts about hum/harmonics here. May be worth reading them. If several repair shops can't pinpoint it...BTW, did you ever rotate tires front to rear and test drive? That was suggested earlier as a basic diagnostic/adjustment. Good luck.

 

No, no… They all hear it, but no one can find it. Even when they put the car on the rack they can hear it! But can’t pinpoint where it’s coming from