2013 Lexus LS 460 Wind Noise (Update with Noise Test)
 

I bought a 2013 Lexus LS 460 few days ago with ~ 55000 miles. I am experiencing very loud noise coming from the windshield starting at a speed > 40 mph, it is very annoying and unacceptable for a car like a Lexus LS 460 where low noise is supposed to be one of its main features.. I don't think it is the noise generated by the " small door triangle" adjacent to the front windows and that has been discussed at length on this forum. Actually, I taped the sides of the small door triangle to eliminate it as a potential root cause of the noise but it didn't make any difference so this confirms that this is not what it is causing the high noise level.

So I took it to the dealership yesterday and the service technician told me that it is related to a design issue with the A-pillars of the car frame that causes wind turbulence and generates the loud noise. I think he maybe correct. I noticed that on the Lexus LS 460 the windshield side trim molding at the A-pillars has a vertical edge of 1 inch high from the surface of the windshield. In this case the wind would be trapped between the windshield and the trim molding vertical edge which would cause turbulence and in return causes the loud wind noise. I am going to think about possible solutions, one of them is to have a windshield side trim molding that doesn't stand vertically over the windshield but rather has a slope that goes from A-pillar down toward the windshield.

Why didn't Lexus design the windshield to sit flush against the A-pillar rather than 1 inch lower than the A-pillar? I can't believe they missed this basic aerodynamics noise issue.

UPDATE with NOISE TEST:

To All:

Thanks for participating in this thread. I went out tonight and conducted a semi-scientific noise measurements inside the cabin. The test was conducted on back roads and highways.

Sound measurement device: Downloaded a sound meter app on my smart phone. Not very accurate but accurate enough.
Location of the sound meter: attached to the heat vent, middle console, driver side. Heat was turned OFF for the vast majority of the test.
Weather conditions: Clear sky, wind speed ~ 10-15 mph
Cabin conditions: All windows are closed, sunroof closed, sunroof roof cabin liner closed.
Test duration: ~ 60 minutes in total, ~ 30 minutes back roads, ~ 30 minutes highways

Results:
Back roads: 52 to 62 dB noise level, car speed 25 to 45 mph. Average noise level 60 dB.
Highways: 63 to 68 dB noise level, car speed 55 to 85 mph. Average noise level 65 dB.
Car engine ON but in Idle: 42 to 44 dB noise level.
Hitting a pothole can add 5 to 7 dB to the overall noise depending on the car speed and the depth of the pothole
Passing cars can add 2 to 3 dB to the overall noise depending on the passing car speed
I turned on the heat for few minutes and it can add 5 to 7 dB to the overall noise depending on the fan speed and direction of the heated air inside the cabin.

The question is the following: Are the noise results above considered "quiet", "semi-quiet", or "loud" for a Lexus LS 460?

The windshield is not a Lexus stamped OEM, it is PGW type glass, but I doubt that this is the problem. A windshield can be a noise problem if badly installed and air leaks by causing "whistle" or "whining" type sound. In my case it is wind turbulence noise.

Here are the facts:

All LS460s and LS600s have been exceptionally quiet cars, except for those cars that had the trim defect on the doors and a few that developed puckered window gaskets. When people first ride in these cars they frequently comment about how quiet the cars are. This is not a kind of subjective quiet - people agree that they are as quiet or quieter than any other automobile they have experienced. There is nothing wrong about the design that would cause them to be noisy, regardless of any technician's opinion.

Although acoustic glass offers some advantage, it would likely be difficult to actually demonstrate that without instrumentation and rigid test conditions. You should get satisfactory results, as to noise, with any kind of glass.

If you are experiencing noise in your LS460, then you need to try to determine: a) does your car separate you from outside noise adequately, or b) is your car making more noise than other cars?

If your car does not separate the cabin adequately from outside noises then you would look at the door trim, windshield installation, the sun roof, window gaskets, door gaskets - things like that. Another way to think about this is your sense of noise from other cars - do they seem louder when you are stopped in traffic?

If your car is making more noise than it should, that may be an indication that some of the under-shielding is hanging down or something like that. You can get an idea about this by positioning a friend near the roadside and driving by and getting their opinion as to whether your car is much louder than others.

And, of course, you have to consider one or more defective tires.

All good points you mentioned below. There is no doubt that this 2013 LS 460 is generating much louder wind noise than my previous 2010 LS 460.

The door trim, door gasket, window gasket are in excellent shape. The sunroof is not the root cause because when I close or open the cabin roof liner under the sunroof the high noise level remains the same. I had to replace the windshield yesterday because of road chips, but same wind high noise level with the new windshield as the old one (both are not Lexus stamped OEM). Glad you mentioned the undercarriage shielding, it is possible that plastic undercarriage shield is not tight but I would have assumed the Lexus technician would have noticed it yesterday when he put the car on the lift for an overall check, I will check it again.

If I cannot fix the noise issue I guess I have to live with it, I doubt that I can return back to the dealer and get my money back because the lemon laws may not cover "wind noise" but rather safety and mechanical issues.

The moldings are in very good shape on both windows.

You should not have to "live with it." Fixing it should not be difficult or expensive.

I would bet money the issue is your aftermarket windshield...may not be the glass itself but how it was installed.

Your 13 should be quieter than your 2010, not louder.

It didn't make any difference in the noise level inside the cabin even when I installed a new windshield yesterday, non Lexus OEM, but the guys who installed it assured me they did it properly. Also if I have to assume bad noise installation the air will be leaking from very narrow areas between windshield and car frame and that sound will be more like high pitch "whistling" or "whining", what I am hearing sounds like turbulence.

Its impossible to say because those apps vary so widely, were they dB(A) weighted, etc. Were you holding it at ear level or down in your lap? Has an impact.I have two apps, one registers 58-59 on the highway at 75 MPH, one registers about 61. Your numbers don't seem crazy high, and depending on the app could be totally normal. Just because it doesn't register on a dB meter though doesn't mean there isn't an issue.

Bottom line, if there is wind noise in your 2013 that was not present in your 2010, something is wrong.

Another question, do you have paint protection film on your side mirrors? If you fold the mirrors in when you are driving, does the sound go away?

It could be something as simple as one small piece of trim out of place.