I have a 2006 xA auto with 1100 miles on it. Ever since I got it, it's had a sticky shift, usually when accelerating from a stop and turning, where it sticks between first and second and kinda jerks through the shift. I figured it would die off after the break in period.

So a month passes, still has a funky shift, and the car throws a CEL. I take it to the dealer to get the code read, and it's a code the dealer's never seen- crankshaft position sensor malfunction. They gave the car back to me, said it was testing fine. I asked if they'd noticed a bizarre shift, they said no. They didn't really know how to fix this error so they erased the code and gave it back to me without doing any work really, and said to bring it back if the code came back, and it hasn't. They said it was my aftermarket cruise sending the code, which i think is BS.

Anyway, about a week later I am driving home on I89 in Vermont when suddenly my car engine brakes with no input from me. We're talking high revs, lost 10mph in a few seconds engine brake. I put my foot on the brake to turn off the cruise and it stopped, so i reset it and it didn't do it again. I was going about 65.

So I'm on the highway again yesterday, trying to get through a crappy interchage between I91 and I391 in MA, and the car does it again. Randomly slows down rapidly, revs high, then returns to normal. It was like the car dropped gear to accelerate, and then forgot to accelerate. I wasn't doing anything special and I didn't hit the OD off, which I thought might have been the culprit last time.

So now it has the random sticky shift when it's accelerating, and also this random downshift at highway speed. It's impossibly annoying to drive a car that jerks along through it's shifts (now it jerks through downshift to go up hills too, like it hangs in neutral and then engages, almost like it would when driving a manual). I can take it to the dealer but the last one didn't find anything and I can't replicate it with any regularity. I bought the car in march so obviously am a little upset it's behaving funny already.

does anyone have ANY idea what could be going on to cause the jerky shifting and inappropriate downshifting? I'd like to go to the dealer armed with some information before the problem gets worse, which apparently it has with more miles driven. Fluid levels are fine, and the cruise was installed after the jerky shifting at low speed started, but before the random downshifting at high speed started.

Anyone out there with some input???

 

I dunno what you drove before... but I think I've had a similar feeling. From what I think, it's normal for the shift between 1st and 2nd to be a bit "sticky" as you're calling it. Granted (and I think you have one... ) it's a automatic tranny, different transmissions from different makes are all different in their shifting as well. I'm coming from a '01 civic auto... I didn't help much, did I?

 

I drove a '95 dodge before this. I've never driven a car with that kind of jerky ride before. Doesn't seem normal. Even a poorly driven standard rides smoother than this car does on one of its bad days.

 

I just re read your statement of the problem a little bit more carefully. If this is happening within the first few minutes of driving, it could just be your engine warming up. Check to see if your blue "cold engine temp" light is still on when the problem occurs. You can do a search in the forums, but when the engine is cold, it will rev higher to warm up the engine before using its full potential of gears.


From what I just quoted from you, it sounds like you may have a torque converter problem. You might get it checked out at a local AAMCO if your dealer isn't quite clear on what the problem is. Your transmission definitely has a problem if this problem is occuring while the engine is warm and ready to go. Have you been shifting to 2 and 1 while driving? Or idling in Neutral? Make sure you have braked to a complete stop before changing from P to D or to R.... i think this makes sense. Hope things go alright!

 

it does it when the temp light is off as well as when it's on. I haven't shifted to 2 and 1 and I only idled in neutral once in heavy traffic. I come to a complete stop before shifting.

All the high speed decelerations have occurred well after the engine warmed up.

 

imma thinkin it might have to deal with the shifter linkage and/or the kickdown linkage

 

Could this be the auto tranny shifting management thing? On mine, when going down a hill, if I take my foot off of the gas, or even slightly touch the brake pedal, it will downshift to use the engine as a brake. Its supposed to do that according to the owners manual. The computer controls the shifting to give more power going up hills and save wear and tear on the brakes going downhill. Mine doesnt sound as radical as you are describing. And the regular upshifts are pretty dang smooth.