Eric0201

I did more test today. When I use the MT mode and keep gear 5. When the speed around 45 and engine at 1500 RPM, I can hear the droning noise. I also tried gear 4 which is better than gear 5. My friend thinks the noise is from the bottom of the vehicle therefore I guess maybe the Exhaust Center Pipe need to replace. I will check with dealership next week.

DyaDya

Did the deed. At the risk of repeating a lot of testimonials from the last few months I feel the need to post mine as well as this has been an all consuming issue with me for the last year and I'm thinking/hoping its finally resolved. This is for anybody who has been a frustrated silent monitor of this thread like me:

-my car built 7/17 in Canada.
-bought it new 3/18 (one of the last new 2017's as the 2018's were coming in).
-have had the car 11 months and noticed this right away and have been silently monitoring this thread for a year trying to figure out what to do.
-I love the car I guess like you love your kid except there are a few things that drive you crazy but you still love the kid. This issue was driving me crazy. (but i still loved the car. go figure. Really just so great on the freeway and the drone is over by the time you are on the freeway).
-At my 5000 mile complimentary service I had mentioned this to the dealer to look at during the servicing..
-I drove a loaner during the service and it was different but to be honest not particularly much better than mine.
-When i got my car back the dealer said my car was fine and nothing to see here.
-One problem for me is i am all the time I am wondering if it was a real problem or i was just too picky. But this thread is so huge so there really must be something here, right? But am i nut? Or maybe it really it is a problem but I am still a nut? They're certainly not mutually exclusive.
-Just went for my 1 yr/10,000 complimentary service. This time to a different dealer, (one that is actually closer to me). Almost casually mentioned this and said I wasn't sure, but it didn't seem quite right. Please check it out.
-The next thing I know they are DOING IT! Under TIS L-TCI-5050, (i believe).
-I come back to this thread and see a few former posts showing the EXACT same 3 replacement parts.
-Veridct: much Much MUCH BETTER!

A couple of notes. I very loosely held/touched the steering wheel in my fingers to try to gauge the vibration. I do feel some vibration before and after the fix probably not any different and probably not any different than the loaners I have had. My guess it that is acceptable. The car is generally very quiet and "refined" compared to anything i have had in the past so every "little thing" stands out. (Which is why I wasn't sure if the droan was all in my head). But now even in ECO mode the droan is so much better. Could it be better? I am not sure. The car has to make some noise. At this moment I am VERY happy and glad i had it done. (disclaimer: my present mental condition is not predictor of my future mental conditions). For anybody on the fence note this is a $2000 fix, so make sure you do it under warranty if you decide to do it! Good luck to all out there to get your issues resolved. Thanks to all contributing to this thread and keeping this issue alive!!!

Eric0201

UPDATE:
I checked with dealer today morning. They had a 5 mins test drive. The advisor said they also notice the drone noise and vibration during the test drive. He suggest me double check at 1600Km again. They think this vehicle is too new and maybe the noise and vibration will go away by itself. (I don't believe it)
I asked the where is the noise from. They also said they are not sure. I asked replace the exhaust pipe and they said the same issue from 2016 already fixed in 2017 and the noise is different with 2016 mode RX350.

If the issue still be here at 1600Km (I booked an appointment on May 21), they will check again and report to Lexus.

Is there any suggestion for me?

rxtimes2

Eric, I also don't believe that the noise will go away. Drive the vehicle for the requested 1600 Km, and when you go back to the dealer take a copy of the TSB with you. It clearly says the RX models affected are 2016 - 2018.

Eric0201

I showed the document to them. But they said the US version is different with Canada version.
No idea about that. Hopefully they can help me find the issue and fix that. They book a whole day for 1600Km service and give me a loaner.
I think they may replace the exhaust pipe or something else. I try to book appointment on May 17 and they said if they need more than one day to fix the issue then I will wait too many time because May 20 is a holiday in Canada.

Tmymck

It worked on my 2016. Dealer installed no charge.

rxtimes2

Play this video (go in a little over 6 minutes). Is this the noise you hear?

gadgetman1

Service Advisors get paid for warranty work. Don’t let anyone tell you otherwise. Mechanics get a flat rate per hour per job & each job has a suggested timetable. If a mechanic is good, he can finish one job fast & start the next, thereby getting paid for both jobs at the same time. Rude Service Advisors usually equal fired! Their primary job is customer service, not commission sales. The more I read on here about some of these Lexus dealers, the more I feel that Lexus needs to really weed out some of their worthless dealers.

LWechsler

I followed your efforts to solve the engine-exhaust problem and must sat-Your work is an inspiration to all of us.
I will try before I do what you did to use 93 octane fuel for several times before I go to the exhaust.
My thinking is that at low RPM the ignition is to much advanced and therefore the rattling noise.
Sins I cannot change the ignition programing in the Lexus RX 350 computer I will try it with the fuel.
If it works, OK if it does not, I can always try your solution.
By the way, the reason I only now in 2019 mentioned this is because I bought mine as a certified used car with 17,700 miles on it. But the coarse engine was clearly noted, until I got this weekend a 2018 loaner, which was very quite. Thank you for your efforts.
LW

rxtimes2

The noise we are experiencing is not a timing issue (preignition knock), it is an exhaust system harmonic vibration that resonates through the cabin at pretty specific rpm ranges.

LWechsler

To Daniel0429

From the picture with the catalithic converter it looks like the spry of undercoating united between it (converter) to the body of the car.
In such a case, it is obvious that rattling will be transferred from the exhaust system to the car body.
I looked at mine, also a 2016 and saw that someone removed that area of over-spry, so mine has less noise and rattling.
It is possible that the factory or the dealer did that, but very few car owner noticed the noise, especially first car buyers!
So take a look to see if that connection still exists.!

LWechsler

To DyaDya
I guess every body has a different opinion.
I checked with my wife and she likes it, because it sounds like a sports car.
I built the assembly shown on the picture but my wife told me to try the 93 Octane fuel first.
Go figure?!

DyaDya

I'm not sure if you meant that post for me or somebody else talking about other alternate solutions. I simply had the dealer change out a tail pipe, (i think), according to a TSB issued by lexus, (like several other posters). A lot of people have talked about other and their own possible solutions according to their own research. And have discussed that on this thread. I'm just a "dummy" who told the dealer it didn't sound quite right, can you make it better?, (while I sit over there and sip on a cappuccino)? FWIT the droan I heard in my car was not IMHO anything like a sports car. It was just sort of an ugly low hum. Good Luck with getting to a good solution for you!

stevemcb

It did help with my drone to have the TSB done to change the resonator part of the pipe. Not 100 percent but better. Now I have a noise coming somewhere at idle. Working on that next.

DyaDya

Yeah, I agree its probably not 100% better but it did take the "edge" off for me. I will continue to monitor this thread for any new "universal obvious" improvement suggestions but its much more reasonable than it was. I just completed a 3k mile road trip of National Parks. It really shines on the open road and I loved it for that. If all I did was mostly run local errands mostly at city speeds it would be different for me. But I spend a fair amount of time on the freeway so on balance its positive now.