jimbo409

Just bought a 2006 400h with 66m milrs one owner in excellent condition all maintenance done by lexus, my question is.

1 I took the car for a test drive a few blocks and everything was fine. when i got on the expressway to go home the car seemed very loud. i have owned a 98 ls 400 and it was real quiet. i checked to make sure all the windows were closed with the moonroof, it is almost loud enough where a conversation would be hard.


2. on the way home after about 15 minutes it smellrd like sulfuric acid and then it went away./ is this normal.
thanks jimbo, love this forum

rcy

Real loud like an exhaust leak, or just loud when accelerating? The 400h has a CVT, so you will find the engine revs quite high under acceleration (basically redlines itself under full acceleration), creating more noise than a vehicle with a conventional tranny. I also find wind noise from my sunroof to be borderline unacceptable, and it's closed properly. Shutting the sunshade really mutes this noise. If the battery has been disconnected and the sunroof switch not reset, it is very hard to get it to close precisely. It SHOULD auto close with one touch on the switch - if it's not, then the reset needs to be done.

As to the sulphuric acid smell....no idea. Make sure the 12 volt battery in engine compartment is not leaking or something..maybe...

jimbo409

it is not the exhaust,it is definetly wind noise

thomas1

Might be bearing noise....My RX400h made a noticeable noise (like road noise) until I finally pin point the front left wheel bearing...Many have had the rear bearings go noisey...The car is really quiet most of the time but the rear hatch area seems to be the most noisey spot. Still might be the wheel bearings.

rcy

Yes, I find mine to be quite noisy around the sunroof (with the shade open), and my auto close is working properly. In fact, at highway speeds, II find the RX overall to be noisier than other cars I've owned.

The one thing that you might consider is the position of the front roof rack rail. I had to remove the rubber moulding at the very front of mine to get my front rail to move to the most forward position (behind the black moulding in the track that the rails slide in, there is one more slot to lock the rail in the most forward position) in order to mount a Thule cargo box. The wind noise increased dramatically with the rail in that position, which is probably why Lexus hides that slot behind the black moulding. Now that snowboard season is done, I moved the rail back further, and the wind noise is much less.

jimbo409

I wish i would of know ahead of time how noisy these cars were i would not have bought it. i have owned other lexus cars and they were all very quiet on the highway. i might sell this rx i am very upset with the noise. jimbo

rcy

Before you condemn the vehicle, make sure (as someone suggested) it's not a bad wheel bearing.

I had a bad rear driver's side bearing in mine and the 'roaring' noise was extremely loud. Same thing with my wife's 2006 Impala, which was even louder than the RX when it's rear bearing went out. It sounded like the vehicle had a 3" exhaust without a muffler.

jimbo409

how do you check to see if it is a wheel bearing thanks jimbo

Carver

How are the tires? Cupped tires can make an awful roar, very much like wheel bearings. When I got mine at 73k I bought it with the assumption it needed rear wheel bearings but a set of tires and an alignment took care of that.

jimbo409

it does need tires,i am going to costco tomorrow to have a set of bridgestone aleza put on. will let you know

RX330inFL

They are still on sale.

ski2days

Why put inferior tires on a superior car? Spend the $. Love my Michelin LTX. fabulous in snow too.
JUst a thought to consider.

thomas1

I bought the Yokohama Prada and they are like super quiet. I was hoping that would fix my noise, still turned out to be a bearing....All fixed and quiet.

thomas1

sometimes you can jack the car up and spin the wheel and you will hear bearing noise. On mine a clue was that when you made a right turn the noise increased (left bearing was bad)

rcy

The Bridgestone Alenza is not an inferior tire by any stretch of the imagination. It's been quite favourably reviewed here and scored third in it's class at www.tirerack.com vs the LTX which scored fourth in it's class.