Today at 260k my car barely accelerated on cold start at 11am it was not even freezing outside. I changed my trans fluid a month ago. It has no issues before the change and no issues after. This is not the first time I’ve noticed this but it’s rare. What’s going on. It almost felt like it wasn’t in gear and just revving up and not going. I stopped the car and went back to park and then went back to d and it drive nornal. Maybe I was not fully in gear I’m hoping ? If I had turned into a main road I think I would have been hit 08 es 260k miles

 

Any error codes? Could be the solenoids not engaging properly? Intermittent issues are the hardest to diagnose.

 

Possibly you have not put in enough transmission fluid. It expands when warm so the cold makes it contract and the level lower.
Pour in 4 ounces of fluid and pay attention to how it behaves the next day. If a little better, try 4 more ounces.
If that does not help you may have more serious transmission problems.
What brand ATF did you use?

Also if using the overflow tube wait for it to slow to a trickle at the correct temperature method, sometimes it is hard to read when to put the plug back in. See this comment from the BobistheOIlGuy forum:
​​​​​​ It’s not that the overflow straw stops draining, it’s more that the overflow straw slows draining to just the right stream. Goodness how imprecise is that? And that trans starts to warm pretty quickly during that procedure, as it drains, while the engine is warming it up with hot coolant. So the first time I tried the straw, i waited until it was just a drip. When that slipped and you could hear gurgling on hard take-off, I refilled it and drained it and then capped when when the bulk of the draining seemed to slow and it was more of a casually thin stream.” its been fine since then.
And this other comment from Bobistheoilguy:
​​​​​​In the Rav4 forums some new Rav4 owners where complaining about trans slipping in places like Canada and Minnesota during winter. Then went back to the dealers and they added more oil. One mechanic told a guy they get low levels right from the factory from time to time. I too had that issue following the level and temp change over to a tee. I then added another 3/4 qt and all has been fine since. I helped a buddy do his Toyota and we went to the set level and we/i added another 3/4 qt for good measure.

 

Thanks for the suggestions, i changed my trans oil as well and noticed the same problem on cold mornings when stop at traffic light..Add 1/2 qt more trans oil as suggested and problem gone for few days.

 

I had original low trans fluid in a 2013 Sienna I bought used. It did not respond to the accelerator the same as my RX350 and both of them and the ES350 have the same engine and transmission.
When I drained the trans it only drained 1.8 quarts. I always got 2.2 quarts from the RX.

After doing a few drain and fills and adding more ATF fluid the 2013 Sienna drove much better. The acclerator response and shifting was just like the RX350.