python152

hi all

My 2013 RX350 (all-wheel) has a super annoying droning sound when pressing gas pedal - it is not the smooth-humming but a kind of low cat-purring sound that is more pronounced when in low RPMs. The dealership can't tell the problem, Lexus Field Specialist acknowledged the sound and said I am not the first one to complain about it, but he doesn't think anything wrong with it. According to him, this is not the sound of the engine, but the exhaustion system. My overall experience with RX350 is not as good as I had expected: it is nosier than my previous highlander, it is also nosier than my wife's Odyssey.

I wonder if any other users had any similar experience? is there any fix to it?

Thanks

Oliver

Cruiter

Oliver, welcome to the club. If it is something that happens with regularity amongst the RX line than someone here indeed will chime in within a day or so. If you read through these Gen III pages you'll find the car overwhelmingly a favorite to the point folks here sometimes nit pick it on small stuff (all cars have small stuff). I drive the (h) so the sounds are probably a bit different. I did want to mention that one of my past cars a BMW made something similar I think to your description (a purring cat). Turned out it was a problem in the transmission. Do you think yours could be that kind of sound? Just guessing here.

Stay in touch.

rayaans

What is the mileage on your vehicle? Any chance it hasnt been broken in properly? Could really be due to a lot of things, dodgy fuel, oil, check the basics first

MEP7557

Python

It is one of the last petty annoyances that I have yet to deal with on my RX. I think the exhaust makes too much noise for a Lexus. Lexus did this on purpose to "butch up" the RX. I wish they had not done that. I have been to the dealer to complain and they just say it is by design. I hope the next gen Lexus will go back to the Library theme. Save the exhaust note for the F-Sport.

Droid13

I'm not sure if the RX350 has this, I think the RX450h does (my Camry Hybrid definitely did), but in any case I've heard this type of complaint before where the muffler has a bypass valve so that under full throttle there is less back pressure to provide more power. If the valve gets stuck open, the vehicle sounds unusually loud at low rpms when it would usually be nice and quiet. It's like having a hole in the muffler.

python152

Andy's description is pretty close to what I "feel": like a hole in the muffler ... I bought my car with only 30 miles on it, now it is 800 miles. But I hear this droning sound more often now days, not sure if it is my psychological stuff in play: as you pick it up the first time, you subconsciously look for it. Had the car for a month now, and still not quite enjoying it.

The dealer suggested a trade-in, but it will cost more than I like plus it seems a bit absurd to trade in a car I just bought. The car I test drove doesn't seem exhibit the same problem (they have to move the car from another dealership, which I didn't spend much time with). Not sure if I should blame Lexus for producing cars with inconsistency or just a norm of variation. Lessons: spend more time with the car you are going to buy, prefer the one on the lot already.

Oliver

Droid13

I looked it up, the RX350 DOES have this setup, as per lexus web site:

Sevn86

My engine is loud at low RPM's when warm at times. it is very annoying but i seem to have gotten use to it now. dont hear it as much. Mine doesn't sound like a cat but the engine is louder then i would have liked in a Lexus.

Aron9000

I'm betting its the butterfly valve in the muffler that is getting stuck open that you guys are hearing.

I know Corvettes have a similar feature so they'll pass drive by noise regulations, when you put your foot down it sounds like the gates of hell have opened up.

Have a friend drive your RX while you stand on the side of the road. Have him drive by at "normal speeds" under light throttle, then have him fly by you at WOT. If its anything like the Corvette, you should notice a huge difference in the exhaust note when he passes you, thus the muffler bypass is working correctly.

User 41924

I have never heard exhaust noise in the cabin of ANY of my Lexus vehicles! Even with the windows rolled down. Being quiet is a marketing point for Lexus, and to think you can hear exhaust noise in the cabin of your RX tells me there is clearly something wrong. This is not to say that you can't hear the engine! That would be a different story, and I'm sure you can tell the difference.

If you can really hear the exhaust, take it back again, and tell them it is unacceptable. To have the Lexus Field Specialist suggest there is an exhaust noise, but nothing is wrong is ridiculous. It makes me nuts, that every time someone has a complaint, the first response is to cover their backside and tell you it's operating as designed. It is NOT "performing as designed!

In my humble opinion, you should expect them to resolve your issue, and not give in until they do.

corradoMR2

Python152, I've been in a latest gen Highlander and Odyssey and the RX is definitely quieter at all speeds. I would agree with the posts above that there can be an issue with the valve in the main muffler. Insist on a side by side test drive with yours and a demo on the lot or go to another Lexus dealer as they can vary significantly in customer service.

svetlin55

my 2010 rx350 doing the annoing exhaust noise only when in motion when i,m pressing gas pedal and rpm are above 1500/at every speed 10 mph,20mph,30mph ......60 ,70mph./!but when the car is staing on P and i press the gas pedal to 1000,2000, 3000 ,4000 rpm no such a laud exhaust noise.what is this overloading to the exhaust sistem,
sv.

Droid13

It is still possible that what you describe is a similar problem. There is significantly less exhaust system pressure when fast idling an engine in "P" compared with when the engine is loaded as when used to move the vehicle.

GoGiantsNJ

I like the deep throaty exhaust note on my '12 RX. I don't have any droning noise luckily. I don't hear the exhaust too much from inside.

svetlin55

Is it posible that noise to be from the pipe sucking air for the air filter, somebody said, it faces cabin wall?