frank357

Hi there,

Since I have the car, the feeling on the 4th gear is weird. When I shift on the 4th gear, after a few second, its like the car shift a second time but on the same gear(lower RPM). Its the feeling I get(like an overdrive?)

I dont think its due to a slipping transmission, but Im curious to get your opinions

Thx

sunamer

does it only occur when the tranny is cold?

frank357

Everytimes I shift from the 3rd gear in manual mode

arentz07

If it's only at lower RPM, this is probably just the torque converter doing torque converter things. The RPM will naturally rise up a little higher while the car is accelerating and will settle down if you let of the throttle or at certain higher speeds while cruising... I don't know all the parameters, but suffice it to say that the RPMs will bounce around quite a bit in normal driving. If not, can you describe what you were doing? Manual/auto? Normal/sport? etc.

frank357

I did a video 5 min ago ahah. More easy to understand with that

So, its only happen in 4th gear when I shift from the 3rd one and in manual mode. Its only happen once when I shift from the 3rd. If I stay on the 4th gear, slow down and accelerate, that not happen. That happen to random RPM, approximately after 2-5 sec I shifted from the 3rd gear. You will see on the video, the RPM and sound drop a bit but I still throttle. I can feel it a bit when I accelerate more hard but less noticable

arentz07

I guess you've got an exhaust? That was a deeper sound than expected.

Anyway, I think it definitely looks like torque converter nonsense. I never experienced this in my 2021 IS 350 however. Is this the AWD model or RWD? That may explain it, if there's a difference between yours and mine.

richieca

You can try changing the transmission fluid if you have not already to see if it makes a difference.

frank357

Yep, I replaced mufflers by resonators

Its the AWD model

rVague

Just drove my 2023 IS and mine doesn’t do this.

LOrtiz87

My 23 is awd those this evern at WOT redlining the gears.

iamroddy

It's just the torque converter locking up...nothing unusual.

InveredMP

Normal.

Filler

mallybandz

my 2015 is350 does the same exact thing. i was wondering if my tranny was going but idk it drives fine otherwise