Your car has the same problem as mine and many others on this site. Lexus has been stone walling on this issue and I am getting ready to file a Lemon Law complaint.
I think we might have to join together in a class action suite against Lexus. I have been trying to get this problem fixed for six months. Lexus says a fix is coming but it never
comes. There is something wrong with many of these RX 2016 transmission. It is very frustrating that Lexus is build on this infallible reputation and yet are willing to risk
that reputation by not recognizing this problem and fixing it. A recall ala Volkswagen will be quite damaging in stock price and reputation. Better to recognize the problem
and fix it they stick their heads in the sand.

 

did you try the tsb? A number of us have and it's still no good. Either a few days or weeks later it goes back to crap. I'm with you on the lemon complain...please keep this thread updated on your progress.

 

Agreed this whole powertrain is a joke, between horrible shifting characteristics, vibration and drone I cant wait to get rid of this thing.
Lexus is without a doubt the wrost vehicle I have ever owned, and I have owned a lot of new cars. I think a class action law suite needs to be the next step.
Count me in....

 

Premium gas came up earlier in this thread and for some time I thought it made a difference only to see the hesitation come back. For kicks, I went back to premium for the last two tanks, and the shifting and hesitation during acceleration are much improved. not 100% but it's noticeably better this time around. Will see if it continues. Anyone else see the hesitation improve with premium gas?

 

I notice a difference from tank to tank and it doesn't matter what grade I am using. I can fill up with Premium and it runs questionably. Then fill up again with the same fuel from the same place and it runs great. Same for regular fuel as well. Vehicle seems to be sensitive to various tanks of fuel. Been running great for weeks and boom, fill up and it doesn't run as well. Next tank back to great.

 

Since new I have always had a rough/buzzy idle. I switched to 93oct. a couple of months ago and the idle has been rock solid. I did notice some improved performance and better gas mileage. The hesitation issue is really sporadic. At time it recacts fine and others I get a couple of second delay before a down shift occurs. I have minimized the drone by driving the vehicle in manual almost all of the time now. I strat in 4th which is the default and hold the gears out to about 2500rpm. When I come aroud a corner I downshift back to 4th and no drone. This transmission is certainly capable of smooth shifts, they just have the programming all wrong. I no its all about fuel economy but I havent seen any real change in gas mileage. Still averaging 24mpg.

 

I've been driving my '16 RX 350 in S-mode (manual) and Sport powertrain setting as a workaround to the rather poor responsiveness one gets when in just plain D (Drive) mode. (I have had the transmission TSB applied and feel this improved the system somewhat.) As "tdjacw" notes above, the transmission itself is very smooth. It's just the programming of the shift points that as tech guru, Tony Northrup, would say are, "just awful." When starting up the car in the morning I switch to S6 and then turn the round, driving mode select switch to Sport. This gives me much better responsiveness without the sluggish sensation one experiences in D (Drive). Most of my driving is within the city so I rarely need to use S7 or S8 so I initially set it at S6 and go. As an aside, engine vibration coming up through the accelerator pedal remains a problem and big annoyance.

 

I have been following this thread for months. My wife's 16' RX350 F Sports just got back from the dealer with the following comments; " Was able to duplicate rocking / shudder feeling, slight hesitation felt at times. Advise customer to use premium fuel as well as sport mode to eliminate shudder / rocking feeling. Lexus is currently working on calibrations for these issues".
The above comments are from a Lexus FTS. Does anybody else have documentation of the problem and has anybody requested the vehicle be bought back?

 

interesting they didn't apply the tsb at minimum. Hope this means they are working on another fix as the original tsb has questionable effectiveness.

As as for my premium gas experience, I'm sad to report that it's back to crappy on my 4th tank. It really seems random when it happens but man does this tranny like 4th gear. Car quickly shifts to 4 before most cars touch 2nd gear!

 

TSB was done back around April time frame. Dealer has verified twice it took.
Lexus flew in a FTS to look at car last month, he is the one that noted the issues on last report.
I'm personally done with the car and wondering if anybody else has documentation from the dealer agreeing there is an issue?

 

Honestly, I can live with the hesitation. Its the vibration felt through the floorboards thats driving me nuts. Its been warm so I have been using the AC and that is just compounding the problem. This engine does not like to be under any kind of load under 2k rpms.
Worst case scenario is slowing down turning a corner going up an incline with AC on, the engine vibrates and buzzes like a chainsaw.
I know I sound like a broken record just never experienced this kind of issue with any other manufacture. Lexus you truly lost my business, cant believe I have had so much better experience with Chevy and Dodge. You know the old saying, fool me ounce!!!!!!!!!

Anyone on the edge of purchasing this vehicle should really think twice. If you get one with this issue there is no fix. Lexus will just tell you its normal unless of course you like to gamble with your hard earned money..

 

My hesitation is minimal, if any, but I have been trying the sport mode and sport+. Getting used to the touchy accelerator in these modes, but it totally eliminates any hesitation. I have not noticed any significant decrease in mpg. I still drive kind of conservatively so maybe that's why? In normal mode I think they still need to tweak it a bit. It's just a little dumbed down. If you drive extremely slow and come to full and complete stops it works fine. But any kind of spirited driving (and we're not talking race mode) it's just a little slow for me.

 

I have a 2017 RX350 that was purchased in January 2017. I really noticed an issue in February when climbing a hill from a dead stop. The transmission has always wanted to upshift very quickly from day one (I suppose for LEXUS to meet EPA numbers), but it REALLY wanted to continue to upshift before even getting to 1500RPM on hills. It was very sluggish and I really had to step on the gas pedal to get it to down shift and get me up the hill. Anything cruising above 40MPH doesn't seem to be an issue. Like others have stated on the previous 400+ posts, the 8 speed transmission is terrible at upshifting in ECO, slightly better in NORMAL, and feels substantially like a 6 speed RX Generation 3 model in SPORT with much quicker acceleration from a dead stop. I didn't really see it as a safety issue until I was on the interstate the other day and was going to pass someone in the left lane from the right lane. The vehicle hesitated for 2 seconds prior to getting enough power to accelerate. That was certainly a game changer.

I will be taking it to the dealer service department soon. This is an issue that can be difficult to describe to a service technician even on a test drive. What is the best way to describe the behavior to the dealer for those that have had success in dealing with service departments on this issue?

 

Don't expect any fix, mine does exactly the same thing even after the TSB was applied. I now drive in manual all the time. I up and down shift when I need to.
I had the same experience on the highway when passing, at least a 2sec delay. Very hard to diagnose because it doesn't react this way all the time but I'm not taking any chances with the safety of my famlly.

 

It is known issue with those tranies. It has dog clutch(3 of them internally). It gets worse in COLD weather. Strictly software programming issue. Until then just drive in sports mode. BMW, or Audi with their trannies don't seem to have same issues.