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Rev dip issue

"M" Specific discussion
NavZ
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Posts: 91
Joined: Thu Jun 19, 2014 8:21 pm

Rev dip issue

Post by NavZ » Sat Sep 23, 2017 10:55 pm

NavZ wrote: Wed Sep 06, 2017 9:15 pm Mine had the same problem, couldn't find the fault.
When the service was due and sparks replaced, it went away :thumbsup:
As mentioned before, it seems to be caused by different things for different cars.
I'd start with cleaning the ICV and doing normal (relatively cheap) service items so that the car benefits whether or not the issue is resolved.
Called it :poke:
2009 Z4M Coupe (TiAg) 80k KM

goon
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Location: Swansea

Rev dip issue

Post by goon » Sun Sep 24, 2017 6:13 pm

Mine used to do this regularly and it was quite annoying, I just got used to it and would use the accelerator in a more progressive way when driving. When you stop and think about it you would never be able to induce this "fault" whilst driving the car anyway.

Lower
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Posts: 352
Joined: Sat Feb 26, 2011 11:16 pm

Rev dip issue

Post by Lower » Sun Sep 24, 2017 6:48 pm

Fingers crossed for you.

With my car it takes about 3-4 weeks after a dme reset for the symptoms to become noticeable again.
57 Z4MC Interlagos blue, Champagne leather, Carbon Dash, SatNav, Bluetooth, Cruise Control, Logic 7, Heated Seats, Rear Park sensors, Isofix and airbag disable switch for the ideal family car :)
Now Sold and replaced with a M2

Sam1977
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Joined: Thu Aug 10, 2017 5:59 pm
Location: Spain

Rev dip issue

Post by Sam1977 » Mon Sep 25, 2017 1:06 am

Lower wrote: Sun Sep 24, 2017 6:48 pm Fingers crossed for you.

With my car it takes about 3-4 weeks after a dme reset for the symptoms to become noticeable again.
Thanks - well I have nothing but time I guess.
BMW Z4M INTERLAGOS BLUE
Other tin:
Porsche 911 Turbo S / Boxster S
BMW E60 M5 / E38 740i / E46 320d / E36 316i / E46 330Ci (Time Attack car)
Mercedes SL500
Hyundai Accent Copa (Andalucia Cup) x3
Audi A6 Avant x2
Nissan Navara
Fiat Punto Sporting

Lower
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Posts: 352
Joined: Sat Feb 26, 2011 11:16 pm

Rev dip issue

Post by Lower » Mon Sep 25, 2017 1:44 pm

What is strange about this issue is that changing things unrelated to the problem seems to do something to the DME that resolves the problem for a while.

I had my ABS pump refurbished and when that was refitted the problem went for a while. As it did when i cleaned the ICV and when the DME has been reset at a service.

The problem goes for a while and then gradually creeps back. Really frustrating as on each occasion you think its fixed....
57 Z4MC Interlagos blue, Champagne leather, Carbon Dash, SatNav, Bluetooth, Cruise Control, Logic 7, Heated Seats, Rear Park sensors, Isofix and airbag disable switch for the ideal family car :)
Now Sold and replaced with a M2

Sam1977
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Posts: 62
Joined: Thu Aug 10, 2017 5:59 pm
Location: Spain

Rev dip issue

Post by Sam1977 » Mon Sep 25, 2017 7:31 pm

Lower wrote: Mon Sep 25, 2017 1:44 pm What is strange about this issue is that changing things unrelated to the problem seems to do something to the DME that resolves the problem for a while.

I had my ABS pump refurbished and when that was refitted the problem went for a while. As it did when i cleaned the ICV and when the DME has been reset at a service.

The problem goes for a while and then gradually creeps back. Really frustrating as on each occasion you think its fixed....
To be honest thinking outside of the "M car" box - changing bad plugs (or coils in the case of the other similar thread) is not really unrelated to the problem. I am not saying I have cracked the case on the rev dip issue - its very possible that the DME is as you suggest just relearning around the problem and it will return. To give a comparison, I race a Hyundai in a one-make series. This thing all of a sudden was very slow starting which is a big problem on the grid where you have to turn the engine off between the 5 and 1 minute sirens. I was convinced it was a fueling issue. Changing coils and leads - completely solved, fires up on the button. Point being bad leads, plugs, coils all will cause some kind of rough running, misfire, hesitation etc.
BMW Z4M INTERLAGOS BLUE
Other tin:
Porsche 911 Turbo S / Boxster S
BMW E60 M5 / E38 740i / E46 320d / E36 316i / E46 330Ci (Time Attack car)
Mercedes SL500
Hyundai Accent Copa (Andalucia Cup) x3
Audi A6 Avant x2
Nissan Navara
Fiat Punto Sporting

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