Know why I think Lexus knew about this the whole time? On my 2002, I always wondered why when you use the auto open function of the moonroof, that it opens only about 98% of the way. I found out by accident one day that if you hit the open switch one more time, the roof will open about another 2 inches. But lookout, the resonating sound will now start because of the moonroof being ALL THE WAY OPEN. I can't remember if I had the windows up or down, but it starts at about 25 mph and is deafening. If you close the moonroof and then auto-open it again, it goes away. Crack it open the additional 2 inches and it comes back. Tell me that wasn't why Lexus Lexus designed it to not open it all the way. Sneaky!!!!

 

Hmm, I've never experienced this in my 2002. I've opened my moonroof all the way, as you describe, dozens of times. The buffeting sound only occurs in my RX 300 with the back windows open...I've heard of this phenomena on 99-00 models, but not on the 01-03's.

 

I noticed that same thing steevr did, but our Sequoia's sunroof does the same thing. If you do open it all the way by pusing the slide open button again you will get the buffeting. IMO, they designed the sunroof right by having it open to the right position automatically.

 

The buffering sound you heard when the back window open is called the cabin's pressure. My GS does the same thing. It's just the air rushing through the cabin or going out, depending on the difference between the inside temp. and outside temp. of your car. As soon as you slightly open another window, the noise go away.

 

My RX is 2001. I do get the buffeting. Hurts my ears. But that's physics. It is natural.

 

Although some are worse than others, you can creat buffeting in almost any vehicle with the right combination of opening sizes for the sun roof, side windows, vehicle speed, wind direction outside the vehicle and, yes, niow roof racks! Just adjust windows (and roof racks) to give you the least buffeting.

Buffeting is actually a resonant pressure wave (standing wave again!) set up in the vehicle, just like a flute if you play or when you were a kid and would blow across the open top of an empty pop bottle to make that beloved tugboat horn sound that you impressed your mother with!

 

This happens more in NEWER Toyota/Lexus vehicles...the GS (2000) does it, and my mom's Highlander REALLY does it, but no matter how hard i try, there isn't anything close in my 95 ES. The altezza does it too, from what i know but i dont recall the sc430 doing it...maybe its built "different" cuz its a convertible (which in itself creates different cabin pressure problems).

 

Think of your Lexus as a musical instrument..........ederny is precisely correct in his explanation.

This is not a new phenomenon, btw. Same situation in my Prelude(s) back in the mid 80s. Laminar airflow across the top of the car will produce it (if the sunroof hole is the right size), disturbance/deflection will reduce or eliminate it (which is why you used to see so many wind deflectors attached to cars with sunroofs; the small popup deflector inside the sunroof was insufficiently sized).

It's just physics................

 

mooretroque is right. The popup deflector, try depressing it while you are up to speed, you'll notice the buffeting effect that it prevents with the sunroof open to the correct size.

 

On my new RX330 I tried lowering one and then the other back window and the noise was incredible and painful to the ears. Couldn't last more than a few seconds before having to close the rear windows. This was without the moonroof open. I don't understand the physics but it did surprise me how bad and painful the noise was.

 

Well derek, you've certainly contributed a useless post. WJBOSWELL may have brought this thread back from the dead but it's not so redundand as the discussion centered around the '99-'03 RX whereas WJBOSWELL's buffeting with his '04 RX shows that this is still an issue with the second generation RX.

 

eeekkkkk!!! derek, just a hint, but it's really not wise to antagonize the mods. Something tells me that your second post may get the boot..........

WJBOSWELL, the buffeting/resonance/helicopter noise (pick your term, it's all the same) is actually a relatively common phenomenon in the last 20 years in cars with sunroofs (which is also, probably not coincidentally, the same timeframe as the common appearance of factory sunroofs, as opposed to T-tops, aftermarket holes, and other stuff of similar nature that dates me as one of the older pharts on this forum). It's why many sunroofs have small popup wind deflectors (that don't work well, but just try holding one down to see how much worse it can be).

And, as previously pointed out, it's just physics..........

 

Respect.

 

Thanks mooretorque but there is hardly any problem with the helecopter noise in my new BMW 530i with the sunroof open. I think Lexus should have spent a bit more time on the problem but otherwise we love the RX330.

 

Not a problem with the Honda Accord, Toyota Camry or Solara. Looks like this vehicle needed some more time in the wind tunnel. Good aero-engineering design could solve this issue.