Stuttering

[motorknut]

It hasn't been back to BMW since my last visit. To be honest I was pretty annoyed with them. Their attitude was 'We can't see a computer fault so we can't diagnose the issue unless it's occurring when we have the car' Also 'Can you not bring it in when it's happening?'
Err, it's intermittent and I could be 30 miles form you when it happens. Also it could stop doing it on the way to you, so the answer is NO! I can see their point but less than great customer service IMO.

Unless it throws a dash fault then I'm basically stuck with it happening from time to time.

Interestingly, it seems to happen less with higher octane fuel onboard although that could be completely coincidental. Next month I'm back in the office again so the car will be getting more usage. Let's see if it starts occurring more frequently. If it does, BMW will be getting the car until they find the fault.

I’ve been running premium 98 octane gas in my Zupra since day 1, and this hesitation only started about 15 months into ownership. Coincidentally, after I had the brake safety recall work done.

The dealers always try to replicate the fault before they proceed with repairs, but intermittent faults are a pain. What I’ve done is provided evidence like dash cam footage and the sensor reading logs from BimmerLink.

Have you considered running a BimmerLink with an OBDlink reader to observe readings when you’re driving? I also picked up the shadow HPFP codes with BimmerLink - but those were triggered by long crank start ups. The hesitation doesn’t trigger any noticeable codes, shadow or otherwise.

[BrianD]

I've had the same issue with a flat spot/hesitation when either pulling away from a stationary position or when almost stopping then acelerating away since the end of November last year. This only appeared to happen after my dealer had updated the software, and have been through is it the petrol or a sensor scenario. I decided to book the car in with my dealer last Friday. As expected there were no error codes logged and the technician wasn't able to replicate the hessitation either. Obviosly it must be a known issue as they did mention that the delayed / sluggish response is a fault caused by incorrect application valve timing in the DSC, and they are not able to fix the fault until software is available in July 2022. Hopefully, this will fix the hessitation issue that I am experiencing, and it's not something that I have yet to notice!

[motorknut]

I've had the same issue with a flat spot/hesitation when either pulling away from a stationary position or when almost stopping then acelerating away since the end of November last year. This only appeared to happen after my dealer had updated the software, and have been through is it the petrol or a sensor scenario. I decided to book the car in with my dealer last Friday. As expected there were no error codes logged and the technician wasn't able to replicate the hessitation either. Obviosly it must be a known issue as they did mention that the delayed / sluggish response is a fault caused by incorrect application valve timing in the DSC, and they are not able to fix the fault until software is available in July 2022. Hopefully, this will fix the hessitation issue that I am experiencing, and it's not something that I have yet to notice!

You mention you had a software update - is this the safety brake recall? The throttle hesitation started in my car after the safety brake recall work, too. But my long crank start up issue was there from day 1.

I have been trying to ask my local Toyota dealer to check with HQ on any potential fault that BMW is working on, but they don’t seem to have any such info. They have agreed to change the HPFP on my car to try, since the long crank start up throws a HPFP low pressure shadow code on my BimmerLink app, and low fuel pressure is observed on the sensor readings I took during these occurrences. But this piece of info on a known dsc/valve issue makes me wonder.

Does anyone else have a long crank start up issue too?

[Sladester100]

Hi all, I was directed to this thread after seeking help on bimmerpost.

….

These are my observations:

• Hesitation occurs within about 500m of driving from start up.

• Time engine has run doesn’t seem to make a difference, as I’ve tried letting car warm up too. Still occurs.

• Not seemingly related to traction as roads always dry for my experiences.

• Power resumes after about 1-2 seconds without needing to depress the pedal much more

• Almost always occurs only once during a drive. Once, occured twice in one drive.

• Has occured twice in a single day, different drives.

• both cold or warm starts.

• both flat or on upwards inclines.

The feeling is like fuel starvation, and I wouldn’t expect rpms to bounce otherwise. I’m having to send my car back into Toyota, but previously they picked up nothing on their scan tool and it’s almost impossible to replicate it on demand. My guess is hpfp mechanical issues.. at least I hope it’s just that. A software fault would be impossible for Toyota to fix on their own. Before seeing this thread, I started to think it was a Toyota tuning issue

The throttle hesitation leaves no shadow codes when I check with bimmerlink. Only the long crank start up triggers hpfp and valvetronic threshold warnings (the latter is a new development)

This is exactly what I’ve observed, brilliant description!

No long crank start issue on mine

[motorknut]

I've had the same issue with a flat spot/hesitation when either pulling away from a stationary position or when almost stopping then acelerating away since the end of November last year. This only appeared to happen after my dealer had updated the software, and have been through is it the petrol or a sensor scenario. I decided to book the car in with my dealer last Friday. As expected there were no error codes logged and the technician wasn't able to replicate the hessitation either. Obviosly it must be a known issue as they did mention that the delayed / sluggish response is a fault caused by incorrect application valve timing in the DSC, and they are not able to fix the fault until software is available in July 2022. Hopefully, this will fix the hessitation issue that I am experiencing, and it's not something that I have yet to notice!

Interestingly enough, my car has been with my local Toyota dealer. They finally opened a case with HQ, and just informed me that after performing a series of tests on the car, they do not believe the fault to be mechanical in nature. They are advising for a software solution , and this is expected for September. Seems to make sense, alongside the bmw update expected for July.

Thing that pisses me off is that likely, Toyota knew of this issue and has not communicated the warning to the dealer network or owners. Maybe it’s cos not all cars are suffering this glitch.

[captainchadl]

I have also just started experiencing this issue while trying to leave my neighborhood at a stop sign. I am going to contact my service center about this hesitation.

[motorknut]

I have also just started experiencing this issue while trying to leave my neighborhood at a stop sign. I am going to contact my service center about this hesitation.

Hope you have luck with the service center, do share your findings.

[Sladester100]

Well.

Here’s something for you all.

I had a moan at my dealership about this, especially as the car is 2 years and 11 months old… the end of warranty check seemed a great time to have a bit of a moan.

Obviously the tech couldn’t replicate the issue, because isn’t that always the way! They called and told me the good news and I pushed back a little after reading on here about throttle control issues so they went back and spent a bit of time re-searching,

Then as if by magic I got a call to advice that they think they had identified the issue… it’s a software problem
Yes I know you’ve just rolled your eyes too. But… wait for it… there’s a PuMA measure!

“B48C & B48D - Jerk during drive off after engine start”

It’s new! It was circulated to their systems on the 09th May!
Typically, there’s still no fix. Awaiting an update apparently. But is down to the DME/ECU.

Im just trying to get some paperwork and I’ll update!

[captainchadl]

That is good news that they are aware of the issue and good be fixing it. I missed my appointment.

[Sladester100]

Hey. Further I’ve obtained the following info from a snapshot of the printed sheet the tech had;

“B48C & B48D - Jerk during drive off after engine start”
GB SEL-SEL-P-12-20000802666201-01 - 09/05/2022

After he engine start, a short jerk occurs once during drive off.
The drive off behaviour is then completely normal.

The complaint only occurred if the DME has gone to sleep before the engine start,
The complaint occurs only once during a driving cycle at the first drive off.
The automatic engine start is not affected

No relevant fault is saved in the fault memory

Vehicles affected;
F39, F40, F44, F45, F46, F48, F54, F55, F56, F57, F60, G29
Engines:
B48A20MQ (B48C), B48A20O1 (B48D), B48B20OQ (B48D)

I couldn’t see the bottom bit of the page but I think that was it, basically no fix but highlights a DME issue causing jerky engine pull away. The tech said it didn’t 100% match the symptoms I mentioned as the complaint description appears more mild but anticipated that might be them playing it down so thinks it’s the same thing.

Also under vehicles affected, I couldn’t see the first inch as his finger was in the way!

[motorknut]

Hey. Further I’ve obtained the following info from a snapshot of the printed sheet the tech had;

“B48C & B48D - Jerk during drive off after engine start”
GB SEL-SEL-P-12-20000802666201-01 - 09/05/2022

After he engine start, a short jerk occurs once during drive off.
The drive off behaviour is then completely normal.

The complaint only occurred if the DME has gone to sleep before the engine start,
The complaint occurs only once during a driving cycle at the first drive off.
The automatic engine start is not affected

No relevant fault is saved in the fault memory

Vehicles affected;
F39, F40, F44, F45, F46, F48, F54, F55, F56, F57, F60, G29
Engines:
B48A20MQ (B48C), B48A20O1 (B48D), B48B20OQ (B48D)

I couldn’t see the bottom bit of the page but I think that was it, basically no fix but highlights a DME issue causing jerky engine pull away. The tech said it didn’t 100% match the symptoms I mentioned as the complaint description appears more mild but anticipated that might be them playing it down so thinks it’s the same thing.

Also under vehicles affected, I couldn’t see the first inch as his finger was in the way!

Interesting, but It doesn’t match the observations in my Zupra either. I’ve had the hesitation occur twice on the same drive too. and this report also looks to be related to the B48 variants and not the B58 models.

Fingers crossed if it does fix things for your car.

[Sladester100]

Interesting, but It doesn’t match the observations in my Zupra either. I’ve had the hesitation occur twice on the same drive too. and this report also looks to be related to the B48 variants and not the B58 models.

Fingers crossed if it does fix things for your car.

You know I didn’t even click that this was all the B48 engines when I read it or posted. Well spotted

[Ard M40i]

I have a similar problem with my M40i (B58 engine). It happens about once a month. It starts immediately after starting the engine and only the first seconds when driving off. After that, it continues to happen during the complete ride (only when driving off). To stop it from happening I have to turn off the engine for about 3 minutes. I've already been to the BMW dealer. They hoped that the software update from the end of 2021 would help to solve the problem. Not a known problem at my dealer and no data logs. After reading this forum I will go back to the dealer again. Apparently I'm not the only one with the problem. I'll keep you informed when I know more.

[Pondrew]

Hi,
I have seen this problem discussed on another forum (regarding the B58 and ZF gearbox but not the Z4).
As the running gear is the same this MAY be relevant.
The consensus elsewhere seems to be gearbox related; not fuel or throttle. Software, specifically.
May help, but I don't know.

[motorknut]

I have a similar problem with my M40i (B58 engine). It happens about once a month. It starts immediately after starting the engine and only the first seconds when driving off. After that, it continues to happen during the complete ride (only when driving off). To stop it from happening I have to turn off the engine for about 3 minutes. I've already been to the BMW dealer. They hoped that the software update from the end of 2021 would help to solve the problem. Not a known problem at my dealer and no data logs. After reading this forum I will go back to the dealer again. Apparently I'm not the only one with the problem. I'll keep you informed when I know more.

Since it happens a few times during the drive, could you try hitting the traction control button once? Some ppl believe that resolves it, but I can never validate the theory since it usually happens once during my drives.