[saintpatty]

Greetings. I've owned the car for a couple months. When in manual mode under light acceleration my shifts are not smooth. Feels like the car is lurching forward. It progressively gets better as I climb the gears but first and second are bad enough I tend to avoid manual mode at low speeds. Anyone else's car exhibit this behavior?

Another note, under moderate acceleration in manual mode I'll occasionally feel a slight thump from the drivetrain. It's subtle but feels like there's excess slack somewhere in the drivetrain. The two symptoms are unrelated.

[Humdizzle]

The 1-2 shift sometimes lurches for me when the car is cold. After that it's fine. What year/model is your car?

[saintpatty]

Originally Posted by Humdizzle

The 1-2 shift sometimes lurches for me when the car is cold. After that it's fine. What year/model is your car?

14 335 m-sport 20k miles

It's behaves that way even when fully warm.

[elistan]

Originally Posted by saintpatty

Greetings. I've owned the car for a couple months. When in manual mode under light acceleration my shifts are not smooth. Feels like the car is lurching forward. It progressively gets better as I climb the gears but first and second are bad enough I tend to avoid manual mode at low speeds. Anyone else's car exhibit this behavior?

Another note, under moderate acceleration in manual mode I'll occasionally feel a slight thump from the drivetrain. It's subtle but feels like there's excess slack somewhere in the drivetrain. The two symptoms are unrelated.

Is this a new behavior, or something your car has always done? (Albeit for the short while you've owned it.)

When shifting from 1st to 2nd, the engine's rpm drops - if the shift is done slowly, the revs fall on their own and there's little impact to the car. If the shift is done quickly, however, that rotational energy transfers to the car and it feels like a lurch forward. When I'm in manual mode at moderate to high throttle application, I definitely feel the lurch - and I really like it.

So it could be that you're just feeling the physics of energy transfer.

But on the other hand, that doesn't rule out some potential issue with your transmission that causing shifts to be executed improperly.

[otay]

I've got the same car. "Sloppy", "lurching", "not smooth"...it's hard to describe issues like this with words.

Disclaimer: I'm not an expert, but this is what I've concluded.

Have you owned or driven a recent BMW before this one? If not, you will find that this AT is more "sport" oriented than others, and you will feel the shifts. Depending on certain variables (like how hard you're getting on it, whether or not the lever is to the left, Sport mode engaged, etc), you'll feel it more at certain times than others. It seems it's actually programmed that way. I like it! Bangin' the gears.

If it feels more like a "lag" from when you shift to when it actually engages and goes, that could be an issue. I had my tranny replaced for this lag between lower gears, because BMW could not figure out what the issue was (long story).

Can you describe better what's happening?

[pz619]

I don't think it's necessarily slop but I think it's just the aggressive nature of the transmission. I think you feel it more at lower gears. On my car a hard 1-2 shift at full throttle will also trigger traction control which further feels like it's lagging the car. Sport+ generally fixes this.

This transmission will not be as smooth as others in manual mode, which is it's fastest shift setting. Keep in mind this transmission pretty much shifts at DCT speeds.

[saintpatty]

Originally Posted by otay

I've got the same car. "Sloppy", "lurching", "not smooth"...it's hard to describe issues like this with words.

Disclaimer: I'm not an expert, but this is what I've concluded.

Have you owned or driven a recent BMW before this one? If not, you will find that this AT is more "sport" oriented than others, and you will feel the shifts. Depending on certain variables (like how hard you're getting on it, whether or not the lever is to the left, Sport mode engaged, etc), you'll feel it more at certain times than others. It seems it's actually programmed that way. I like it! Bangin' the gears.

If it feels more like a "lag" from when you shift to when it actually engages and goes, that could be an issue. I had my tranny replaced for this lag between lower gears, because BMW could not figure out what the issue was (long story).

Can you describe better what's happening?

Lag is a good way to describe it. Slow shift followed by an awkward engagement that causes my head to rock. The effect is not extreme but pronounced enough to make me think it's not functioning as intended. I plan to take it in but wanted to hear other's experiences.

FWIW, I had an X3 28i as a loaner last month and it did not exhibit this behavior.

[Kafkaesque328]

When not under heavy load, the transmission does a brilliant job on its own, left to its own devices. I don't see the point in shifting manually just cruising around town. Its not like the car is ever in the wrong gear. This transmission is one of if not the best in the business. It also isn't like there is some tactile reward from pulling the paddles. It isn't like shifting a proper manual gearbox, even remotely. I like using the paddles if I am driving winding roads and really want to hold gears to my spec but even then, sport/sport+ does an almost identical job.

I also stay out of sport mode at low speeds because it shifts more abruptly then is needed at low speeds and putting around town and holds gears a little long for my taste. I mean its an automatic transmission afterall, a big selling point being ease and smoothness. I guess I don't understand OP's motivation but each to their own. Like why not be in a car with a 3rd pedal?

[bimmer456]

I would leave it in auto after a cold start to allow the engine to warmup first. I usually start with sport mode and then shift to sport +. It seems to me that the torque converter locks up pretty soon when starting off so sport mode helps the throttle response to compensate better for this. I don't use manual mode. I may use that once it is at operating temperature. There may be some exceptions to the rule but I try to keep the rpms lower. Try giving it less throttle in sport until it warms up. If using manual mode shift a little later but don't rev it too much either. I noticed if starting off in comfort mode it may lurch after a cold start so try using sport instead to compensate for the early locking of the torque converter.

[saintpatty]

Originally Posted by Kafkaesque328

When not under heavy load, the transmission does a brilliant job on its own, left to its own devices. I don't see the point in shifting manually just cruising around town. Its not like the car is ever in the wrong gear. This transmission is one of if not the best in the business. It also isn't like there is some tactile reward from pulling the paddles. It isn't like shifting a proper manual gearbox, even remotely. I like using the paddles if I am driving winding roads and really want to hold gears to my spec but even then, sport/sport+ does an almost identical job.

I also stay out of sport mode at low speeds because it shifts more abruptly then is needed at low speeds and putting around town and holds gears a little long for my taste. I mean its an automatic transmission afterall, a big selling point being ease and smoothness. I guess I don't understand OP's motivation but each to their own. Like why not be in a car with a 3rd pedal?

Let me be clear that I love the transmission. I almost don't miss my manual. Almost.

I've owned manuals exclusively since I've been able to drive so almost 20 years. I keep it in auto most of the time around town but I prefer the control in moderate to heavy traffic on surface streets. The car can't anticipate when I may need a lower gear or maintain a gear for any given situation.

[bimmer456]

Originally Posted by saintpatty

Let me be clear that I love the transmission. I almost don't miss my manual. Almost.

I've owned manuals exclusively since I've been able to drive so almost 20 years. I keep it in auto most of the time around town but I prefer the control in moderate to heavy traffic on surface streets. The car can't anticipate when I may need a lower gear or maintain a gear for any given situation.

Most of the time the transmission is in the right gear in sport + but sometimes I use the paddles to intervene or put it in full manual. Most folks who drive manual prefer to be in a lower gear than the computer selects for fuel economy.

[saintpatty]

Originally Posted by bimmer456

I would leave it in auto after a cold start to allow the engine to warmup first. I usually start with sport mode and then shift to sport +. It seems to me that the torque converter locks up pretty soon when starting off so sport mode helps the throttle response to compensate better for this. I don't use manual mode. I may use that once it is at operating temperature. There may be some exceptions to the rule but I try to keep the rpms lower. Try giving it less throttle in sport until it warms up. If using manual mode shift a little later but don't rev it too much either. I noticed if starting off in comfort mode it may lurch after a cold start so try using sport instead to compensate for the early locking of the torque converter.

I have no problems with cold behavior and I always leave it in comfort/auto. I rarely engage sport and don't see a need for sport + on the street (non-adaptive).

[bimmer456]

Originally Posted by saintpatty

I have no problems with cold behavior and I always leave it in comfort/auto. I rarely engage sport and don't see a need for sport + on the street (non-adaptive).

You said you're in comfort and shifting manually that it lurches in 1st and second? Maybe if you use sport and manual shifting it will be less noticeable.

[saintpatty]

Originally Posted by bimmer456

Most of the time the transmission is in the right gear in sport + but sometimes I use the paddles to intervene or put it in full manual. Most folks who drive manual prefer to be in a lower gear than the computer selects for fuel economy.

Everyone has different driving habits and preferences. But that's not really the issue at hand.

[saintpatty]

Originally Posted by bimmer456

You said you're in comfort and shifting manually that it lurches in 1st and second? Maybe if you use sport and manual shifting it will be less noticeable.

Pretty sure I tried that and saw no improvement but I'll give it another go and report back.

[F32Fleet]

Nothing to see hear. You're complaining about how an automatic performs a 1-2 shift in manual mode. The shifts won't be smooth.

[XutvJet]

What you're feeling is likely a torque management system at play in the lower gear upshifts and maybe the traction control nannies working. Lots of newer automatic transmissions employee a torque management system. Some do it better than others.

Have you tried driving in DSC Off to see if it feels the same? If it's quicker and smoother in DSC Off then it's likely the traction control nannies. With my 6MT car, the power is far more consistent and generally stronger in DSC Off. All other modes you can tell the nannies are controlling/limiting things.

[Kafkaesque328]

OP, I will say that when I do drive in manual mode, I select 2nd gear from a stop and go from there because shifts from 1-2 are never smooth except under wide open throttle.