[Monkeyboxers]

My cars driven 16K KMs and today when I drove the car, I've noticed there's a strong jerk from stand still to maybe 2nd gear, not always but enough to feel it and made me uncomfortable. Below is what I've noticed and tested:

1. Jerk/jolt movement in both Comfort and Sports mode
2. Only present going from stand still. I would guess going from gear 1 to 2.
3. The jerk/jolt is present both at smooth and "harder" acceleration
4. I've also noticed the floor vibrate. At first I thought it was my H&K system and I shut it down. Then I thought it was someone else's subwoofer. It's a slight vibration on the on left foot, near center axle. Right hand driver here.
5. RPM gauge doesn't go up and down when idle
6. The car has been on the road for around 3 hours. Driving on both congestion and highway.

Also, I've had the car for nearly 2 years, so I'm think my throttle control hasn't changed.

Has anyone experienced this? Oh, it's a 8AT 330i M Sport.

[VVlasy]

I noticed the same on my 440i. It is currently undergoing ATF flush and change, will let you know how it goes.

[Monkeyboxers]

Looking forward to your response. Not pleasant to drive!

[chiefneil]

Mine did the same for a while the first year or two when it was new. It's since settled down and behaves more reasonably now. Try eco mode when you're stuck in stop and go traffic, that seemed to help smooth it out a little bit.

[VVlasy]

So my report. I have a 2016 440i GC xDrive with 20k miles

I will first outlay some symptoms I had. Violent jerking when letting off throttle at lower speeds (10-15 km/h). Jerk/punch/clunk sometimes when letting off throttle while cruising. Noticably slower shifting, especially when cold and downshifting (braking to red light), sometimes would jerk you back and forth like a new driver in a manual car.

So I went for the ATF flush and change (600$ out my pocket). The tech from the indy drove with me and said I dont know what is bad shifting, but I stood my ground that I want it changed.

Picked it up and immidiately noticed the slower downshifts were fixed, and it was definitely smoother, tommorow morning I will know for sure if it truly improved.

Some jerk is sometimes still there, its less violent tho. I believe xDrive has something to do with it (its a known piece of junk), I may change the fluid in it too...

And the fluid was not in a good condition. Changed to very very dark green, was not burnt, but definitely not lifetime.

[M2_MEDUSA]

If it's under warranty get a diagnosis ran on it you don't need a cel for it it'll still show if it jerks at idle it's your valvetronic motor

[VVlasy]

No diagnostics will diagnose jerking unless there is something broken, which is too late then. What he is seeing now are symptoms of something coming. I dont know how are the wait times for his dealer. But I have to call in almost a month ahead...

Another quick update after today mornings cold start and run. Much much much smoother. There is still simetimes some small jerk, but I attribute that to the xDrive transfer case.

[M2_MEDUSA]

That's incorrect, My car was jerking and nothing was broken and I had no check engine light and all symptoms were good. They ran a diagnostics and boom "Valvetronic Motor Fault"

[Zentan]

Any mods? If you have an aftermarket intake, rough gear shifts are common.

[otay]

Originally Posted by Monkeyboxers

My cars driven 16K KMs and today when I drove the car, I've noticed there's a strong jerk from stand still to maybe 2nd gear, not always but enough to feel it and made me uncomfortable. Below is what I've noticed and tested:

1. Jerk/jolt movement in both Comfort and Sports mode
2. Only present going from stand still. I would guess going from gear 1 to 2.
3. The jerk/jolt is present both at smooth and "harder" acceleration
4. I've also noticed the floor vibrate. At first I thought it was my H&K system and I shut it down. Then I thought it was someone else's subwoofer. It's a slight vibration on the on left foot, near center axle. Right hand driver here.
5. RPM gauge doesn't go up and down when idle
6. The car has been on the road for around 3 hours. Driving on both congestion and highway.

Also, I've had the car for nearly 2 years, so I'm think my throttle control hasn't changed.

Has anyone experienced this? Oh, it's a 8AT 330i M Sport.

Is what you're describing a delay of any sort? Like, you give it some throttle and nothing happens for a second then it jerks forward?

This has always happened to me to some extent, especially from a stand still. Think it's bad programming, somewhere between throttle and transmission. Putting it in ECO seems to help. Hate it, but have learned to live with it.

[M2_MEDUSA]

Originally Posted by otay

Is what you're describing a delay of any sort? Like, you give it some throttle and nothing happens for a second then it jerks forward?

This has always happened to me to some extent, especially from a stand still. Think it's bad programming, somewhere between throttle and transmission. Putting it in ECO seems to help. Hate it, but have learned to live with it.

If your saying it jerks forward that's called torque lmao. It's going to happen. When u press the gas your creating g forces and those g forces make u jerk when ur on the throttle. Unless I have ur situation wrong .

[Monkeyboxers]

Lol, yes I know what torque is and feels like. I love it. It feels more like a bad upshift.

No mods. Stock standard. I keep the throttle at the same pace and it just feels like the rev stops/hangs then when it upshifts it just jerks.

So I've driven it for 2 days after it happened and it has stopped. Weird

[otay]

Originally Posted by IssaF32

If your saying it jerks forward that's called torque lmao. It's going to happen. When u press the gas your creating g forces and those g forces make u jerk when ur on the throttle. Unless I have ur situation wrong .

Very nice technical explanation.

In my situation, there's a brief delay between pressing the throttle and actually moving. Then when you do move, it jerks. Kinda like you let the clutch out too fast, but this is 8AT. I've learned to be very smooth and careful in first part of throttle pedal application when pulling away from stop. Worse in Comfort, a bit better in Sport, but still there sometimes.

Oh yeah, and it's intermittent, so the dealer can't find anything wrong.

[chiefneil]

Originally Posted by IssaF32

If your saying it jerks forward that's called torque lmao. It's going to happen. When u press the gas your creating g forces and those g forces make u jerk when ur on the throttle. Unless I have ur situation wrong .

You might want to google the term "throttle tip-in".

IMHO BMW has had issues with throttle tip-in since they went to throttle-by-wire in the E46. If you drive an older BMW with a mechanical throttle cable (or a cheap POS rental car), you'll immediately notice how smooth and immediate the initial tip-in is.

Modern BMWs starting with the E46 have a slight pause before it reacts. Meanwhile drivers are naturally accustomed to moving their foot through the pedal to the desired position. So whereas an E36 would immediately react as you move through the first .1" and steadily pick up speed while you move to the 1" position, you get an F30 that doesn't react until your foot reaches the .5" position which then gives you a jerk as if you suddenly jabbed the gas. Using made-up numbers as an example there, of course.

With my F30 I adjust by doing a slight touch on the pedal, wait a fraction of the second, then start easing into the throttle as I feel the engine react. When my F30 was doing the jerky behavior I think I mentioned upthread, even with that slight pause I'd still get a jerk. But it's since smoothed out.

All of the above just my personal experience/observations having owned an E36, E46, E53, E70, and F30. YMMV.

[otay]

Originally Posted by chiefneil

You might want to google the term "throttle tip-in".

IMHO BMW has had issues with throttle tip-in since they went to throttle-by-wire in the E46. If you drive an older BMW with a mechanical throttle cable (or a cheap POS rental car), you'll immediately notice how smooth and immediate the initial tip-in is.

Modern BMWs starting with the E46 have a slight pause before it reacts. Meanwhile drivers are naturally accustomed to moving their foot through the pedal to the desired position. So whereas an E36 would immediately react as you move through the first .1" and steadily pick up speed while you move to the 1" position, you get an F30 that doesn't react until your foot reaches the .5" position which then gives you a jerk as if you suddenly jabbed the gas. Using made-up numbers as an example there, of course.

With my F30 I adjust by doing a slight touch on the pedal, wait a fraction of the second, then start easing into the throttle as I feel the engine react. When my F30 was doing the jerky behavior I think I mentioned upthread, even with that slight pause I'd still get a jerk. But it's since smoothed out.

All of the above just my personal experience/observations having owned an E36, E46, E53, E70, and F30. YMMV.

Thanks, chiefneil This is exactly what I'm trying to explain.

Wondering if it's any better with 6MT...

Not sure if this is what OP is asking about though.

[lkstaack]

Originally Posted by otay

Thanks, chiefneil T
Wondering if it's any better with 6MT...

My 335i with 6-speed will occasionally buck in first gear when it's cold. I just slip the clutch and shift into second quickly and it goes away.

[carbon_f32]

I get this jerking issue only when I am brakeing. 2019 bmw 440i gran coupe. 28k miles