Hard shifting when accelerating at low speed (1.4T Auto 2013 Hatch LTZ)

[Eranthe]

Howdy everyone,

I'm finding that when I pull out of parking lots and need to push it to merge into traffic (as opposed to accelerating gently, which has no issue), I'm getting a very hard shift intermittently going between 1-2 or 2-3. I don't know which gear specifically is the issue, but it's enough to jerk the car quite noticeably.

I'm wondering if this is something that I should be taking to the dealer, or if it's something that will work itself out. There are no check engine lights on.

Thanks!

 

[SSpeckerwood]

my apologies. I looked right over the fact that it's a automatic.

 

[SSpeckerwood]

re-opened

 

[$ub$onic]

 

[sarahsideways]

I get the same jerk, but it depends on how hard you're slamming the gas. I highly doubt its a problem, might be your foot hitting the gas laying off and going back into it, try it in manual and guage the rpms yourself and see if you feel the same jerk. Could be a problem for you, but I know its user error when it comes to mine!

 

[chrisennis7]

Yea I noticed this same thing!! My 350z was a lot worse though, it even jerked so hard sometimes that the tires would lose traction for a second. It only happened on hard acceleration though.

 

[sx sonic]

If its 3/4 to wide open throttle (WOT) then it is normal. When you give it a lot of gas the Transmission control module changes not only when it shifts, but also how firmly and quickly it shifts. I.e. when your putzing around slow smooth shifts, when you hammer down fast hard shifts.

Sometimes giving it more or less gas right before it shifts can make the problem better or worse, depends how the computer interprets the command to go fast or slow and what it was intially about to do

 

[ungawd]

I think you have to describe this hard shift. Does it feel like it lunges forward with authority? That could be boost. Does it make noise when it happens, a clunk or ching? Does the throttle back off, ala traction control enabling itself, sort of a back-forward lunge? I would test that out by disabling TC/STM and see if it acts differently and smoothes out.

Also what sx sonic said. Test it with consistency. Also note the engine sound or rpm.

 

[Eranthe]

There is definitely not a feeling of it lunging forward with authority. It feels like when my brother was learning to drive stick and he kept miss-shifting. There's no noise that I can tell, and I'm not flooring it, just accelerating up to road speed. I usually drive pretty gingerly because I'm in the land of stoplights and revving the engine is a pointless waste of gas.

It doesn't always happen, either. It's kind of random, which makes it much more noticeable when the car jerks for no apparent reason!

 

[ungawd]

That sounds to me like the torque converter. How many miles are on the car thus far? I ask this because the TCM has a learn mode, while it's in this mode it will be jerky. Mine smoothed out after about 400 miles. I recently tuned so I went through it again. This time it seemed to only last about 150 miles. If the car went in for service it may have been reset. A power surge or dip could possibly cause it to reset as well. I'd give it a few miles if that is suspect and then try to duplicate the problem.

 

[Swordsmith]

Solution:

Step one, trade car in for manual
Step two, keep it in first till your rpm redlines
Step three, coast to next light

No shifting necessary in city driving, only jerk will be the one behind the wheel

 

[ChrisJ]

That sounds to me like the torque converter. How many miles are on the car thus far? I ask this because the TCM has a learn mode, while it's in this mode it will be jerky. Mine smoothed out after about 400 miles. I recently tuned so I went through it again. This time it seemed to only last about 150 miles. If the car went in for service it may have been reset. A power surge or dip could possibly cause it to reset as well. I'd give it a few miles if that is suspect and then try to duplicate the problem.

Why does that sound like a torque converter symptom to you? Unless you are suspecting maybe the lockup clutch is engaging too soon and causing an abrupt jerk? I suppose thats possible........

 

[ChrisJ]

Solution:

Step one, trade car in for manual
Step two, keep it in first till your rpm redlines
Step three, coast to next light

No shifting necessary in city driving, only jerk will be the one behind the wheel

I agree with step one.

Ignore step two, shift as necessary. Follow step three.

 

[Eranthe]

I'm at about 700 lifetime miles on the car. Maybe a tad less.

 

[ungawd]

Why does that sound like a torque converter symptom to you? Unless you are suspecting maybe the lockup clutch is engaging too soon and causing an abrupt jerk? I suppose thats possible........

I presume it is computer controlled, given the nature of the learn. I had an old 350 turbo that was mechanical that had a stall/hesitation feeling every now and then followed by a hard engage, could duplicate it by easing off the gas slightly during shifts. The torque converter was the issue. The stall speed was too high, loose, something. It was pronounced when shifting out of park as well. I snapped a yoke sitting in a gravel parking lot shifting out of park because of it.

 

[ungawd]

I'm at about 700 lifetime miles on the car. Maybe a tad less.

You should be well out of the original learn. I would try to replicate it a few more times and then take it in. A relearn could smooth it out.

 

[ChrisJ]

I presume it is computer controlled, given the nature of the learn. I had an old 350 turbo that was mechanical that had a stall/hesitation feeling every now and then followed by a hard engage, could duplicate it by easing off the gas slightly during shifts. The torque converter was the issue. The stall speed was too high, loose, something. It was pronounced when shifting out of park as well. I snapped a yoke sitting in a gravel parking lot shifting out of park because of it.

Ah I see.