BMW newbie - Thuds/harsh upshifts in SportPlus (B58) normal?

[Emm540]

Thuds/harsh upshifts on recently bought 540i xDrive Touring (LCI)

Hi, I'm new here and recently bought a LCI 540i xDrive Touring.

It's my first BMW and first ZF, so maybe I just need to get used to it.

Loving it overall!

In Comfort, and ECO Pro, the gearbox is lovely and smooth.

But whenever I floor it in Sport / Sport Plus, I feel two what I would call thuds, shunts, jerks or jolts. This isn't what I expected i.e. I thought the B58 accelerated smoothly through the rpms.

It only seems to do this in Sport/Sport Plus.

Before I bought the car, the main dealer replaced the propshaft flexible coupling. On the test drive *before they replaced this, I didn't notice this behaviour flooring it up to motorway speeds.

Googling, it seems like it could be the fuel tank vent valve, CV joint / bearings, engine mount, transfer box (maybe just fluid low/needs replacing), ZF itself (or again just needs new ATF), Vanos solenoids, or mismatched tyres.

My mileage is 68,000 and it's got two Bridgestones at the front, with the same pattern, and two Pirelli I think at the back, again with matching patterns.

I just don't have time to take it back and forth to a dealer or indie to investigate through trial and error potentially over many weeks into months, so thought I would post here to get some initial thoughts on a ZF that's smooth all the time except in kick-down?

[drdino]

Do you get a gear indication on the cluster when in Comfort mode? Ie D1, D2, D3 etc or is it just D?

[MarkJS]

I have the the B58 with the ZF8 gearbox and I have never experienced any of these symptoms. The gearbox is fantastic in all situations/configurations (as is the engine) in my experience.

[danb79]

Yup; in Sport / Sport+ the changes are more aggressive; more so if everything is set to 11

My pals 340i F30 is the same; as is our F31

As soon as they're back in Comfort they're smooth as cream

[Emm540]

drdino said:

Do you get a gear indication on the cluster when in Comfort mode? Ie D1, D2, D3 etc or is it just D?

I think it's just D, but will try to properly observe when I drive the car again later today.

[Emm540]

MarkJS said:

I have the the B58 with the ZF8 gearbox and I have never experienced any of these symptoms. The gearbox is fantastic in all situations/configurations (as is the engine) in my experience.

Hmm, yes, your positive description is what I thought the B58 in mine would be like, so I've got a feeling mine might need looking at. But another reply has just said there's does shift aggressively in Sport+, so maybe this is what I'm feeling...

I'm wondering if the facelist 48v mild hybrid model like mine makes a difference to the ZF shifting, as I can feel regenerative braking very strongly if I full-throttle the accelerator and then lift off entirely rather than modulate the throttle back down again. Which year is your B58?

[Emm540]

danb79 said:

Yup; in Sport / Sport+ the changes are more aggressive; more so if everything is set to 11

My pals 340i F30 is the same; as is our F31

As soon as they're back in Comfort they're smooth as cream

Thanks, this is really intriguing! Yep, everything is set to 'full' in Sport+ on mine, and when I kick-down from say 30mph fully into the carpet, it sort of 'notches' a couple of times before reaching motorway speeds. Maybe this is just normal for aggressive gear changes then. I admit, I only floor it in Sport/Sport+, not in Comfort or Eco Pro, so will see if there's a difference.

[toon10]

I had a 540i xDrive and as mentioned, everything goes very aggressive in Sport +. Sport was my default setting for a combination of throttle response, gearing and useability. Sport + was just used for the occasional fun bit of road. It's the same on my 340i.

[Emm540]

toon10 said:

I had a 540i xDrive and as mentioned, everything goes very aggressive in Sport +. Sport was my default setting for a combination of throttle response, gearing and useability. Sport + was just used for the occasional fun bit of road. It's the same on my 340i.

Thank you

So in Sport +. if you floored it, would you "feel" it change gear, rather than say a linear 3-litre petrol Lexus with a CVT that would just increase speed but without a couple of mini Concorde sound barrier type 'humps' on the way?

[toon10]

Emm540 said:

toon10 said:

I had a 540i xDrive and as mentioned, everything goes very aggressive in Sport +. Sport was my default setting for a combination of throttle response, gearing and useability. Sport + was just used for the occasional fun bit of road. It's the same on my 340i.

Thank you

So in Sport +. if you floored it, would you "feel" it change gear, rather than say a linear 3-litre petrol Lexus with a CVT that would just increase speed but without a couple of mini Concorde sound barrier type 'humps' on the way?

Yes you feel it more in +. I think they're trying to set it up to feel more hardcore in that mode so let you know that you've changed gear!

[drdino]

Sport+ transmission has quite distinct kicks in the upshifts, yes.