5

Many owners of many vehicles report this issue, so am guessing it's not a big problem. The vehicle crawls in reverse or any forward gear until things warm up; normally just a few seconds. ~Thirty seconds has been the longest when it was ~10F outside (car garaged though).

I've owned thirty vehicles but very few automatics. Does anyone know more about them and have an explanation for what is happening?

It has 32K miles now and at 24K miles I did change the Toyota WS entirely out for Redline D6 (because I tow, though original fluid turned out to look fine). It's tricky to verify fluid level but I am very detailed and am sure it was correct; re-checked a week later. Also pan was dropped and filter changed.

Am thinking to pull the battery overnight and reset the ECU. Could add a little more fluid for a week (I don't drive far most days).. fluid expands when warm so maybe a little low?

Also the car has sat for three->four weeks several times this year. On my return it did the same thing just the first time; vehicle crawled for ~five seconds and then it was totally fine including on restarts (until I brought it back to Denver where mornings can be really cold).

3

More fluid is not a solution, check your transmission fluid levels according to your manual and only add if the level falls below what is required. Resetting the ECU doesn't sound like a winner either as the problem only shows itself in cold weather.

Sluggish automatic transmissions in very cold weather is a common issue, the ATF fluid needs to warm up a bit to work properly, so the solution is just to let your car heat up a minute to get it circulating.

  • Thanks for the reassurance. Am only buying CVTs or manuals again from now. This is the first daily-driver auto I've owned and have to say that I'm not a fan. Loved my Prius' CVT and the CVT in the 2015 CRV I bought my wife - both super smooth. Also super easy to change their fluid. – Paul Lockwood Dec 11 '17 at 14:22
  • I've had a number of automatics @PaulLockwood and I've never had a sluggish transmission on any of them, even in Wisconsin winters. I know people who have sluggish autos and manuals in the cold, it seems more the model than the category. If it continues to be a problem there are ATF types for better cold weather performance that you could try. – GdD Dec 11 '17 at 14:42
1

Researching this further, I believe GdD is correct and more specifically it's by design that modern cars delay lock-up to assist heating up the ATF.

The best summary I found (on a Toyota forum):

But when the transmission is cold, the lock-up function is disabled and the transmission behaves like an ancient auto tranny with a lot of slippage. It has two objectives:

  • Running with open lock-up torque converter is inherently less efficient, generates heat and speeds up engine and transmission warm-up.
  • It circulates more transmission fluid helping to equalize the temperature between the engine and the transmission faster.

Link to the quote above: http://www.rav4world.com/forums/126-4-4-mechanical/175897-odd-transmission-behavior-cold-weather.html#post1693665

Update Jan 2019:

  • Resetting ECU clears this issue for a while

  • Issue never occurred while back 12+ months in Atlanta (much warmer there)

  • At -12F (-24C) the transmission took well over a minute to function correctly (was parked outside overnight in Utah)
0

My Dodge Neon 2002 (Auto tranny) used to have this problem. During winter (we have freezing temperatures), it doesn't shift gears sometimes and has low acceleration. Once I got the transmission oil top-up done as a during my normal maintenance check. And it worked.

Though there can be many reasons for this to happen, oil level is the most frequent one.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.