Hesitation problem at various speeds (TSB info post #159)
 

I am a new member and first time Lexus owner of the 2016 RX 350. I am finding a real hesitation issue with my car. I took it into the dealer and after several days told me it is working as it should?

Am I the only one with this problem? Please let me know if anyone else has it. I am in conversation with Lexus HQ about this issue.

Can you provide more details? What exactly do you mean by "hesitation"? Under what conditions/circumstances?

I sometimes feel it when doing a moderate acceleration from stop. And also right after shifting the gear to the next during acceleration, the steering wheel and gas pedal feel a little rough from some vibration. Once it goes to higher RPM or higher speed, everything is smooth again. This is more noticeable if drive in ECO mode. I only drove the car for less than 200 miles. Dealer filled the gas for me but not sure what type of gas. For next tank I will try the premium gas to see if it does the same or better.

Under moderate to lower acceleration the 4RX tends to up shift way too soon. This is due to the programming to save gas. When you want to increase acceleration the tranny has to downshift and sometimes does not find the right gear causing the engine to bog down. I have found that a little more aggressive acceleration to keep it in a lower gear works better for me.

Putting my 4RX in the "sport mode" keeps it in a lower gear, a little too much for average driving. Wish there was something in between. The RX has to shift so many times with the 8 new 8 speed it makes the motor almost feel like the CVT type to me.

I also think this is a transmission issue. It seem like it wants to shift to 2nd or 3rd gar way to early un less you are aggressive with throttle. I find to make a smooth acceleration you have to give a little extra off the line then let up on throttle approaching 3k rpm.

I find it happens at pulling out if I am not fast enough on the gas, when I cruising along with normal traffic and not pushing the gas more than is necessary to pace the traffic. The most recent place I had it was going on the turnpike ramp and while building speed it hesitated quite a bit.

Sounds like many of you think it is the transmission? What can we do to get Lexus to get us a fix? I did notice it was worse in eco mode but still does it regardless of the mod I put it in.

I feel the same thing that is being described somewhere between 3rd and 5th gear. The first thing that came to mind for me the 8spd tranny. I'll bring this up at our first service appointment but it's not bothering my wife so therefore not really bothering me. Hopefully if enough people complain they'll put out an update or something.

Pretty sure it is due to the transmission mapping as if you put your RX in sport mode where the RPMs stay higher there is no hesitation.

I seem to get the hesitation in every setting
 

So you are saying it is most likely a transmission issue, may well be but my Lexus dealer says it is working "as it should" nothing to fix!

If others share this problem with their dealers maybe we can get Lexus to correct this for us?

On my LS460 when in eco mode there always is a hesitation. When I put in ECT power mode it pretty much goes away.

Yep, Eco mode tends to have the vehicle shift to higher gears early to save gas. Problem is the same you get hesitation when wanting to accelerate waiting on the tranny to shift to a lower gear.

Hesitation
 

What I don't understand is when my dealer loaned me a 2015 RX 350 it was powerful, quick and solid acceleration I never had any hesitation. Then I got my 2016 back and it has the hesitation. It seems they need to work the "bugs" out of the 2016.

For now I'll just put the RX into "sport" mode if it really bothers me while driving. But I do plan to bring it up at our next service appointment.

Take care.

Sport mode make the 4RX act really different! Nice indeed.:thumbup:

Larry, sorry you're having problems. Have to point out the 2015 is six speed while your 2016 is eight. From my experience the eight speed in the 3RX F-Sport had hesitation too. There's a thread about it in the forum. But I didn't feel it in a 4RX F-Sport I recently test drove. If anything I think Lexus improved the transmission. And I'm supersensitive to these things coming from a hybrid.

How does your RX drive in other modes? And what did the dealer do to determine your RX drives 'as it should'? Maybe a drive with a tech or service manager is in order. And I know this is probably not what you want to hear but If you want zero hesitation or shifting, then RX450h is the way to go.

Good luck and please keep us posted.