It really could be the spark plugs. Our engines use standard copper core plugs and should be changed every 30,000 miles. They are not difficult nor time consuming to change so even going to a shop and just asking them to install 4 new copper core plugs shouldn't be that bad. Then see if the bucking continues. If it does, perhaps consider having a shop just drain and refill the transmission fluid. As far as I know, the Hyundai 6-speed automatic does not have a changeable filter and has just a drain plug for fluid changes. Again, it should be pretty labor affordable, though the fluid could be pricey.

 

Speed doesn't seem to be a factor, just accelaration.

I would start with spark plugs if they haven't been done in the last 30k, they can cause what you're describing and not throw any codes.

 

Ok, thank you. I will definitely do that. They have never been changed out. It's worth a shot anyway. Thanks so much for your input.

 

You're welcome, let us know how it works out.

 

Yep. Spark plugs will do that. Mine started misbehaving like that around 40,000 miles, spark plugs were the cure.

 

Thank you everyone for your input. I'm going to have the spark plugs replaced. 🤞it does the trick. I'll let you know. Thank you!

 

It’s the plugs, mine did the same thing, I put iridium in and has been flawless ever since. 2015 Jeep Patriot 2.0 engine with cvt here

 

I had the spark plugs replaced a few days ago and so far, no bucking! I haven't driven it much yet so we'll see if it lasts. I can't thank all of you enough for your advice. I'll keep you posted.

 

Thanks for the update!

 

Was it after getting gas ? ⛽

 

No, that didn't seem to make a difference. So far, the spark plugs seem to be doing the trick.

 

I have a 16 patroit,older ones had a rollover valve in tank sticking causing them to buck and stall after fueling. Don't know if jeep fixed the problem for my year. No recall yet. Changed both cam sensors,not as bad now.

 

I just wanted to let you all know that the "bucking" never returned after I replaced the spark plugs, so that was definitely it. Thank you all for you help. I have a another issue happening now that involves the suspension (I think). It's been gradually getting worse. I had it at my mechanics a few weeks ago when it wasn't really bad then and he could find anything. Anyways, it's gotten much worse in the past few weeks. Whenever I'm going slow, especially coming to a stop, it makes a creaking, clunking noise that sounds like it's coming from the front, maybe left front tire area. If I have the car in park and turn the steering wheel to the left and right and you can hear it clearly. It seems to be worse when turning, going over bumps, at slow speeds and coming to a stop, and also when it's warmer out. I'm thinking maybe a tie rod, ball joint, bearing, something along those lines. Any help on this matter would be greatly appreciated. Thank you!

 

Hey, thanks for the update.

Bad ball joints can definitely clunk or rattle when going over bumps.

Creaking / clunking could also be the sway bar links, or the sway bar bushings.

However, clunking when turning and stationary may be a bad strut mount bearing that's allowing the spring plate to bind on the bottom of the strut mount which causes the spring to twist when you turn the wheel, then when there's enough tension it pops free, making the clunk.

I just replaced one a short while ago. It also knocked when going over bumps.

Here's a vid that will give you an idea:

If this is the problem, it's important to get it fixed ASAP or it could ruin the tie rod ends or damage the steering rack.