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Inconsistency in acceleration/downshifting.

28K views 47 replies 16 participants last post by  2014 forte ex  
#1 · (Edited)
I just wanted to know if anyone else has experienced an issue that has been occurring on my 2014 EX.

What I've started to notice is that my car will have good and bad days when it comes to this problem.

When I'm driving on a "bad day" (doesn't matter if it's a residential street or the highway), I notice that when I lightly accelerate to pickup speed (or accelerate at all) there is almost a hesitation and the engine sounds like their is almost too much of a load on it. It sounds "buzzy" and just louder than normal. I actually have to press a little more on the accelerator than normal to get it to speed up. But, when it does downshift, it's a smooth transition, there isn't any jerking or anything. Once it downshifts and I speed up, the engine sounds much louder than normal too. There is a noticeable loss of power, so much that it just takes the fun out of driving the car all together, the car doesn't glide, it feels stiff. The noise level and lack of power remind me of the 4 cylinders from the early 2000s, they were noisy and lacked power.

Now on a good day the car drives normal, like it did on the first day I bought it. It accelerates extremely well, has excellent power and pickup, downshifts at the tap of the accelerator and the engine is super quiet.

I drive with the eco off all the time, the car is just more fun to drive without it.

I'm really surprised that this has happened because I've owned two Kias before this and, parents drive a 2013 Soul, and nothing like this has ever happened. They're solid vehicles.

I haven't taken it to the dealer yet, but I'm definitely going to as it only has 7,450 miles on it.

Any ideas on what it could be? I'm thinking it could possibly be something in the brains of the car, rather than a mechanical issue?

Other than this minor quirk, I'm in love with the car!
 
#41 ·
For those experiencing this issue

I have only two suggestions for those posters experiencing this issues
a) there's an official Kia Forte page on FB...let Kia know your issue with the Forte it'll probably ask you for more details like you VIN to be sent via PM.
b) there's also a Kia Consumer Care user on Twitter (this is LEGIT)...
https://twitter.com/KiaConsumerCare

Send it a tweet and it'll probably ask you for details too.

Hope this helps!
 
#42 ·
I have only two suggestions for those posters experiencing this issues
a) there's an official Kia Forte page on FB...let Kia know your issue with the Forte it'll probably ask you for more details like you VIN to be sent via PM.
b) there's also a Kia Consumer Care user on Twitter (this is LEGIT)...
https://twitter.com/KiaConsumerCare

Send it a tweet and it'll probably ask you for details too.

Hope this helps!
Thanks for the info.
 
#43 ·
Bad gas or letting the tank go on empty for long times.
when that happens again open full throttle when on the highway (best a week after the oil change) this way all the carbon build up, contaminants or fuel tank residue stuck in the fuel system will be expelled. This was the 80s fix the carburetors acted up and still works today.
 
#44 ·
UPDATE: The car had been doing great for about 5 months. A couple of weeks ago I noticed that the issue came back but it was somewhat minimal. So last night I'm waiting in the drive-thru at my credit union. It's a pretty long line and I'm just moving along slowly. Out of curiosity, I put the car into manual mode and of course the display on the dash changes from "D" to "1". The entire time I'm moving along, maybe 3 MPH at a time, the shift changes from "1" to "2" on it's own and stayed there even after I came back to a complete stop. I know in the past when I'm out driving on the road and have it manual mode, it will automatically drop down to "1" when I come to a complete stop. I think it's highly unusual that it changed to "2" on it's own.

When I have the issue where the car feels sluggish, etc, it feels like it could be starting off at a higher gear which would obviously cause sluggishness. Also I noticed that KIA released a software update for the ECU on the 1.8 engine as part of a recall. I wonder if there will be on for the 2.0 anytime soon.

I'm taking it back to the dealership on Monday to inform them of the weird behavior.
 
#45 ·
So ive been following this thread for awhile hoping someone would find a fix. Although at the time, i never had an issue with it.. well just the other week i went out to start the car after work to head home, and when it started, the rpms quickly climbed up to 3000-3500 then dipped down to normal 1500 (cold start) ever the since the the car has been acting as people have described above. inconstant shifting, no power when i lightly get on the gas: it acts as if it doesn't know what im doing. ive reset the ecu and everything, double checked all the connections on my intake, all that. took it into the dealership today and they claim that its fine and they cant find anything. not throwing any codes or nothing. The car just feels off.. it doesn't always do the crazy start thing.
 
#47 ·
Forte 2016 here. Same thing. It just feels weak. Not shifting, the engine. It has bad weeks and good days. Last two times it went back to good acceleration (effect lasted for couple of days):

1. My friend, agressive driver, rushed to airport. Car worked well after this for two days.
2. I changed engine air filter. Worked well for couple of days.


ECU was flashed fresh at dealership a year ago.
 
#48 ·
Has anyone found the solution, I'm have all the same symptoms. Sluggish, sounds weird(louder, muffled), doesn't shift right, revs way past shift point. Fuel mileage is around 19, but before I could get almost 30. If I press accelerator slightly it cycles fine, slow but fine. If I give a little more peddle it's over with, everything goes wrong