[AnthonyR]

Hi all,

Iv noticed noticed that my car wouldn’t automatically change gear from 7th to 8th when driving on the motorway and the gear changes seem a bit odd as it holds on longer. It’s on comfort mode and I have not changed any settings, including the shifter.

I read it may have something to do with the OPF regen, so gave it a blast and also updated my software (as my notifications were stating there is an update a few weeks ago). All seemed well and the car was driving as normal, until a week ago as it seemed to do the same thing. I did another run on the motorway hoping to force a regen, but no joy this time, and it has been a week and it’s still not shifting as normal

Any ideas?

Thanks in advance!!

[CH_M3f80]

Originally Posted by AnthonyR

Hi all,

Iv noticed noticed that my car wouldn’t automatically change gear from 7th to 8th when driving on the motorway and the gear changes seem a bit odd as it holds on longer. It’s on comfort mode and I have not changed any settings, including the shifter.

I read it may have something to do with the OPF regen, so gave it a blast and also updated my software (as my notifications were stating there is an update a few weeks ago). All seemed well and the car was driving as normal, until a week ago as it seemed to do the same thing. I did another run on the motorway hoping to force a regen, but no joy this time, and it has been a week and it’s still not shifting as normal


Any ideas?

Thanks in advance!!

I have the same problem now with my X3MC (no 7th to 8th when driving on the motorway / OPF regen)...but actually no solution from bmw or my bmw garage. They think it could also have a connection with my sport exhaust.... really??! It's a legal one...
Do you still have the problem? If no, what was the solution? They dont know anything actually... :-/

[AnthonyR]

I did a lot of research and the way to regen an OPF is different to the DPF. Basically when you reach norm operating temps, you have to let off the gas and roll so the OPF can regen. That is why a motorway drive is best.
I have BimmerLink so was able to see how much soot each OPF bank had. Initially it was over 5g per bank. I managed to get it to less than 1.5g after a few regen runs.
However, I have now gone for a catback system as I didn’t want this happening again.
So I also have the OPF delete cables and canbus module to stop any EML coming on.
Hope you get it sorted 👍🏽

[ztx84]

The no shift from 7th to 8th might also be to do with your speed and the torque characteristics of the S58. I've noticed mine is less keen to shift to 8th than when I had a 540 (B58 engine), and I think it might have something to do with the S58 having less torque lower down. I might be totally wrong here, so please correct me!

[JDS]

Can you explain the best way to force a regen? This issue started on my X3M about three weeks ago. I asked BMW Sytner Nottingham about it today, and their response was, "it doesn't shift into 8th until 75 mph" - which is absolute BS.

I thought it was due to either the one tank of regualr unleaded I put in it, or that my car was due for an oil change, and it was backing off a little, but what I am reading here makes more sense.

I just saw there has been some of this on M4s in the USA also.

[AnthonyR]

Basically, get the car up to normal operating temps (ideally on a motorway), accelerate and let go off the peddle and let the car cruise. This causes the soot to blow off through the exhausts. An OPF regen is different to a DPF one

[JDS]

Quick update. I tried this last night on a short drive home via the motorway. The car was already at temp before I reached the motorway since I had been driving around town a little beforehand.

I basically acclerated a few times and then lifted off every mile or so. Whislt it made no difference last night, I am happy to report that the car was shifting into 8th "normally" again, at sensible speeds. In the right conditions, the car will shift into 8th as low as 58-59 mph, so I still have no idea what Sytner were thinking with their claim it doesnt shift into 8th until speeds above 75 mph - or maybe it is them that have no idea.

Anyway, thanks for the advice. I may try and incorporate some of this into my driving behaviour on a reasonably frequent basis to try and keep the OPF as clean as possible!

[M4_Randy]

Originally Posted by JDS

Quick update. I tried this last night on a short drive home via the motorway. The car was already at temp before I reached the motorway since I had been driving around town a little beforehand.

I basically acclerated a few times and then lifted off every mile or so. Whislt it made no difference last night, I am happy to report that the car was shifting into 8th "normally" again, at sensible speeds. In the right conditions, the car will shift into 8th as low as 58-59 mph, so I still have no idea what Sytner were thinking with their claim it doesnt shift into 8th until speeds above 75 mph - or maybe it is them that have no idea.

Anyway, thanks for the advice. I may try and incorporate some of this into my driving behaviour on a reasonably frequent basis to try and keep the OPF as clean as possible!

I just got my car back from BMW and have been having the same issues.. before I gave it to them I mentioned that it seems it might need a regen and when I got it back was told I should now take it for a minimum of 1 hour drive at 70 mph to reset the regen.. I have done this as best as possible but not always that easy here in the UK lol..

hadn't worked so far but did you accelerate a few times to normal motorway speed and just take your foot off the pedal? if so for how long or to what speed before you went again?

[AnthonyR]

Yes correct, basically the OPF regens when you let off the gas, you need to keep doing this a few times. Hopefully it will clear. I believe it happens when each opf bank has over 5g of soot mass.

[JDS]

Originally Posted by M4_Randy

I just got my car back from BMW and have been having the same issues.. before I gave it to them I mentioned that it seems it might need a regen and when I got it back was told I should now take it for a minimum of 1 hour drive at 70 mph to reset the regen.. I have done this as best as possible but not always that easy here in the UK lol..

hadn't worked so far but did you accelerate a few times to normal motorway speed and just take your foot off the pedal? if so for how long or to what speed before you went again?

In my experience, the one hour of driving at 70 mph doesn't work.

One of my team members used to work a lot with DPF and OPF filters when he worked at Lubrizol and was quite familar with this issue. He told me that DPF's have active regeneration cycles that are powered by the cars electrical system. However, OPFs, in petrol-powered cars, have no such system. They are regenerated passively, from the heat in the exhaust/OPF filter.

In order to regenerate an OPF, his advice is consistent with that provided on here. You need to ensure that the engine is at full operating temperature, and regenerating the filter basically means burning off the soot that has built up. To do that, you have to stop the combustion by coming off the throttle and letting the car coast. With this lack of combustion, or more accurately, the very lean combustion, the temperature is temporarily elevated, and in combination with the high flow rates achieved from doing this at higher speed, the soot will start to be removed.

I don't believe there is a standard way of doing this. I just made sure that my engine was hot, and then basically did a few cycles of "around" 70 mph and lifted off for as long as was safe to do so, making sure I wasn't compromising other cars. Best done late at night on quiet stretches of road. I probably tried to do this for a couple of days, and now it is back to how it was before. My car will now upshift to 8th as low as 60 mph if I am entering the motorway in a leisurely fashion - which is not too often!

[M4_Randy]

Originally Posted by JDS

In my experience, the one hour of driving at 70 mph doesn't work.

One of my team members used to work a lot with DPF and OPF filters when he worked at Lubrizol and was quite familar with this issue. He told me that DPF's have active regeneration cycles that are powered by the cars electrical system. However, OPFs, in petrol-powered cars, have no such system. They are regenerated passively, from the heat in the exhaust/OPF filter.

In order to regenerate an OPF, his advice is consistent with that provided on here. You need to ensure that the engine is at full operating temperature, and regenerating the filter basically means burning off the soot that has built up. To do that, you have to stop the combustion by coming off the throttle and letting the car coast. With this lack of combustion, or more accurately, the very lean combustion, the temperature is temporarily elevated, and in combination with the high flow rates achieved from doing this at higher speed, the soot will start to be removed.

I don't believe there is a standard way of doing this. I just made sure that my engine was hot, and then basically did a few cycles of "around" 70 mph and lifted off for as long as was safe to do so, making sure I wasn't compromising other cars. Best done late at night on quiet stretches of road. I probably tried to do this for a couple of days, and now it is back to how it was before. My car will now upshift to 8th as low as 60 mph if I am entering the motorway in a leisurely fashion - which is not too often!

Thanks for that, i will try this and hope it will make the difference!

[JDS]

Great. I forgot to mention that you shouldn't expect it to "clear" whilst you are doing the cycles.

With mine, I did the cycles and the behavious remained the same for a day or two and then seemed to reset itself the next time I drove the car, which was the next morning.

I probably did 7 or 8 cycles over the course of 5 miles on the motorway.

James.

[MJBO]

For what it's worth, my car will only auto shift into eighth on the motorway if I am in D1 gearbox mode.

D2 it will sit in seventh at 110 km/h.

[Noddy335i]

Hi guys,
My first post here for a while.
Have just purchased a 2021 M4 comp and noticed at motorway speed 70-75ish the car goes through the gears nicely up to 8th and then drops to 7th. If I speed up to 84 it shifts up to 8th and stays in gear. Slow down to 70 and drops back to 7th.
I have tried the OPF regen by speeding up and slowing for about 50 miles but car still does the same.
That is when driving in eco with gearbox in 1st setting so full eco.
If i shift into manual it will stay in 8th.
Any ideas ?
Thank you

[Noddy335i]

Also I’ve tried the transmission reset with holding the throttle down fully and pressing start before and after, waiting 1 min etc etc….

[AnthonyR]

If it’s still under warranty I’d take it back to bmw. This is happening to a decent number of cars so the dealer should be aware of this.
They will force a regen on it. This is done whilst the car is stationary. Make sure you have a full tank of fuel as well.

[Noddy335i]

Thanks Anthony,
Will take back to dealer and see what they say.
The car only has 9k miles in 2 and half years so possible soot build up due to that?
Will update when resolved…..

[Noddy335i]

The above came up once but not since the attempt at regen

[Noddy335i]

Also the 2:01 never changed when on display

[AnthonyR]

Iv never had that before. Odd why it says dpf as well.
Defo take it to bmw as you’ve only had it recently. Low mileage cars do suffer this more as mine did.
Has your been mapped or any exhaust mods?

[Noddy335i]

Yes I thought DPF was strange too.
Car is under warranty, only had it a week and selected the 3 year warranty pack upon purchase.
Going to ask the dealer to flash the car in case of any previous remap etc.
Also it does have the stock exhaust including OPF filter I can see.

[Noddy335i]

Pleased to report that the car is selecting 8th as it should do today 😊
I do have the fuel warning light on though so hope it’s not just trying to save fuel.
Will fill up tomorrow and hope all remains ok.
Thanks for your replies Anthony 👍🏼