I've noticed that at times. Either there's a glitch in the computer or the car justs acts differently based on conditions.

 

Does it feel like a transmission slip?

 

I've noticed this as well. Could be weather conditions? I know I'm not supposed to but I notice it more when I don't let my car warm up properly. I have noticed it on highway driving too though. I'm sure it's nothing to fret about..I'm still breaking mine in >2000km. If it persists I'll get it looked at.

 

I think what you're expecting to feel is that pin you back in the seat turbo boost thing right?

That doesn't happen all of the time when you put the pedal down, it all depends on how much you open the throttle.

I find that from a rolling start if I put the pedal down quite a bit, the RPM do jump, it makes a lot of noise and doesn't do that whole turbo pin back feeling that we all love.

However, if I'm already cruising along at about 80-90mph and I put the pedal down (not to the floor) but enough - it's there. It kicks right in and pushes you back.

I think it's all a matter of how much you open the throttle. If you mash it down, the engine sucks in as much air as it can and the engine roars. However, if you're already cruising along or not mashing it down, a moderate depression of the pedal will open it up just enough for the turbo boost to be really evident.

Under WOT I never feel the turbo kick me back until I'm up around 60-70mph.

Maybe this helps, I'm just going based on my exp with mine which as 26,000 KM/s on it so far.

 

Thanks all. Doesn’t feel like transmission slip but I am keeping an eye on a weird transmission shifting issue that seems to happen once and a while first thing in the morning while driving down my street. dolsson your explanation sounds logical and it may be related to the speed I am moving and how much the accelerator is being depressed. I will take note of that and see if there is still variation in similar conditions.

 

i have this too. i'm not sure what it is. sometimes it pulls hard even with barely any throttle, and other times it seems like it barely wants to go. Other times the power seems to waver back and forth as the engine revs. there must be a reason they made it do this, but i can't find a pattern (weather, humidity, altitude etc).

 

same issue here

 

Has it happened over an extened period of time? I had something similar happen once - intermittent sluggish acceleration - and took it into the dealer. No CEL, no codes, and they said it felt fine when they test drove it, but suggested a bad tank of gas might be to blame. I thought "BS", but I had last filled up at a different station before returning home on a road trip. I used up that tank and re-filled from my local station. Problem went away and hasn't returned.

Jaeger

 

I had similar problem once but it didn't last. I think a lot of what happens is unless you drive crazy all the time the ecu remembers how you normally drive and adapts both the tuning and transmission to your driving style. When you punch it one day it may take a little more effort (floor the pedal) to get the desired result. I have noticed that if I've been gunning it for a while the throttle becomes a little more responsive. In other words I don't have to step on it quite as far for it to drop 2 gears and take off.

I know the throttle/transmission adaptation happens all the time but whether thats what some people are experiencing is the question.

 

Might also want to check your plug gaps. Real easy to do. Helped me out:
http://www.hyundai-forums.com/230-sonata-yf-turbo/132768-2011-yf-2-0-t-spark-plug-update.html