I was wondering if anybody else had a weird rattling noise coming from/behind the dashboard when the temperature is below 40? The service techs found the noise was coming from the brake booster check valve. They concluded that the noise was normal and that all RX's have that noise at low temperatures. The service manager told me it has something to do with the vacuum created in the brake booster check valve. He said they might redesign the valve, but at this point there is nothing else they can do. I've already contacted Lexus corporate via email and phone. Hopefully if enough people complain a recall/TSB will happen.
Anyone?

 

No dashboard noise on my 2005 RX. Knock on wood.............

 

That's probably because you're in California LexTranny. It doesn't get cold enough. The factory technician told me every RX330 has the noise. The brake booster is mounted to the firewall in front of the driver side dashboard.

 

Seems to be a common thing with the dash. Had ours in 2 times with limited results. We go to Florida for the winter so we miss a lot of the problem. We are back now & have not noticed that it has returned so we'll keep our fingers crossed.
Right now the drivers door is squicking even after I sprayed it, so back to the dealer.

 

Fairly common problem on the 330's. Search the board for "dash rattle".

There have been a couple of TSIB's issued, but it seems that there are several possible causes for the noise... wiring harnesses in the dash, vibration from the defroster vent, vibration noise from the cowl (plastic piece outside the window by the wipers), etc.

Sometimes the solutions in the TSIB's work, sometimes they don't seem to solve it.

 

But for a 40+K vehicle one would think these things would not happen. Just shows to go ya.

 

I have a feeling that all these unsolved rattles and noises that people are having with their RX330's is caused by an undiagnosed brake booster check valve. The dealer had my car for almost 2 weeks and even had factory technicians work on the problem. They kinda found it by accident. Accidentally pinching the line to the brake booster solved the problem. He told me that he could not do that permenantly for safety reasons and that a newly designed brake booster check valve is needed. I think all these people going in and getting felt insulation, dash insulation and other things is trying to cover the problem, not solve the cause. If enough people complain, they will have no choice but to solve the root cause.

I almost gave up on this problem.
Do not give up, call and complain. That is the only way it will get solved.