I just purchased a 2009 lexus is250 with 136k miles.

When I start the car in the morning and drive, the engine revs but car hardly moves.
I can see nearly no movement when the revs go from 1k to 2k.

Once the car is warm(temp gauge is almost centered), this is not the case. Any increase in revs results in reasonable movement of the car.
I would guess this isn't normal for lexus. What should I check?
No dashboard lights. No error codes on the OBD scanner. Tires are inflated to the spec (35 psi front and 38 for rear). Using Auto (not sports shift).

 

I'd start with a transmission fluid level check followed by a flush. The concern is it might be low. If the engine pulls RPM it should move and there shouldn't be change from cold to hot..

if you can DIY, here is a clear method I wrote...
https://www.clublexus.com/forums/is-...a760e-rwd.html

When warm, how does it behave if opened up?

 

When it's warm, even a little increase in rpm results in movement. Completely normal behavior.
I also noticed the cold behavior is in the morning after overnight parking.
If I drive it in the morning and let it rest for 5-6hrs and then drive again, I don't see the cold behavior.

 

Again, check you transmission fluid level as recommended. This is a classic symptom of low tranny fluid level. Have you seen transmission fluid - pinkish on the garage floor? Get it check asap, you do not want to spend big buck for a tranny swap. Good luck.

 

Just place an IR heat lamp under the car directed at the pan to keep it warm 24/7!!! haha! J/K

OP check that fluid. Slipping transmissions burn clutches and self destruct! Not good and it's expensive!

 

Is the transmission oil pan covered by a plastic cover that runs almost half the length of the car?

This is the cover-

 

Finally, I did the transmission fluid refill.

The tough part was getting underneath the car, taking off the plastic cover. Everything that could go wrong did go wrong -
I lost 2 nuts for the cover.
Forgot the 24mm socket. wrench didn't work. With car on jacks, had to bike to the nearest hardware store...good I live close to harbor freight.
Spilled oil while trying to pump it in. I had an extra quart just in case.
While trying to take out the refill bolt cover, I took out the wrong nut. Putting it back was a pain due to small spaces.

After working thru all this crap, I got 3 quarts out and refilled 3quarts plus maybe 1-2 fl ounces.
Didn't see any immediate changes. But in a day, the change was obvious.
There's no revving without movement at cold start.
Car does run just a little smoother.

Should I do a complete flush or just do drain+refill after a few hundred miles?

 

Here's another reason why I am thinking about full flush -

Old fluid was dark brown. Is this expected?



trans oil: old vs new