coilz

This happens to my 250 as well. Usually occurs when tempurature is below freezing. Once you let go of the accelerator the RPM will dip for a second significant enough to cause a s light jerk in the car. But it isnt changing gears.. it does it even with the slightest tap to the accelerator. Usually disappears once engine reaches operating tempurature.

Nathaluc

I was happy to find this thread and subscribed... Experiencing the exact same thing on my 2011 @ 50k miles, only until fully warmed up where it goes away. It's cold here, 15°F to -15°F, however outside temperature doesn't seem to impact as it's been ongoing for a long time. Although others are experiencing this, it never happened on my 2006 through 75k miles and I can't see that it would be normal... Still looking!

Caramelel

It's completely normal. It's a luxury car, the rpm drops to conserve fuel when you're not on the throttle.

KamilSTI

Any solution to this problem? My IS 250 has this problem when the temperature is low.
When I release the throttles, the rpms drops to ~ 0,9-1K and returns to the previous value after a second.

Vovchik

I have the same exact thing with my Lexus IS350 AWD. Especially when its cold

KamilSTI

Exactly. For me, the symptoms have stopped because spring is approaching and the temperatures are higher. I noticed that when the temperature is lower than -1 degrees Celsius the problem returns.
I heard that there is an air temperature sensor in the MAF sensor, but I have not tried to replace it yet. Maybe someone has information if I am right.

KamilSTI

This is what it looks like to me.

jizz4jazz

iTrader: (1)

is250 does the exact same thing

lilwatty19

Transmission could be slipping

KamilSTI

Then the car would do it all the time. This problem is only in winter when the temperature outside is below zero.