M5 F10 dct problems
Discussion
Plumo27 said:
Hello All, I'm new to the gassing station and looking for some help!
Bought an M5 f10 couple of weeks ago, 62 plate with 5k miles.
I'd like to know if anyone else has had similar problems to me with the dct transmission.
The problem occurs at low speeds 30mph ish, in drive auto mode, when slightly decelerating, ie just slightly lifting off the throttle before you brake. (Ie going down a slight hill before braking) The revs start to increase slightly, say from 1500 to 2000 rpm but feels like the clutch is slipping and then at about the 2000rpm mark its like the clutch bites and jerks etc, the car will keep doing this until you either brake or accelerate. The gear number on the dash doesn't show a change to a lower gear. It seems to be worse in wake up mode "efficiency" but I also get it in "sport". The cars going in to bmw on Monday but other people's simlar experiences would be helpful. By the way other than this I really like the car!
Cheers
Just read through this and a bell rang in my head….I'd read something about gradients in some guff BMW put out about the DCT years back.Bought an M5 f10 couple of weeks ago, 62 plate with 5k miles.
I'd like to know if anyone else has had similar problems to me with the dct transmission.
The problem occurs at low speeds 30mph ish, in drive auto mode, when slightly decelerating, ie just slightly lifting off the throttle before you brake. (Ie going down a slight hill before braking) The revs start to increase slightly, say from 1500 to 2000 rpm but feels like the clutch is slipping and then at about the 2000rpm mark its like the clutch bites and jerks etc, the car will keep doing this until you either brake or accelerate. The gear number on the dash doesn't show a change to a lower gear. It seems to be worse in wake up mode "efficiency" but I also get it in "sport". The cars going in to bmw on Monday but other people's simlar experiences would be helpful. By the way other than this I really like the car!
Cheers
Now, this is from the BMW Media Information Publication relating directly to the DCT Transmission which in the M models, BMW call the M Double-Clutch Transmission (I suppose to distinguish it from the Normal DCT…???)…
Titled - Assistance when setting off on an uphill gradient
"Gradient detection by the M double-clutch transmission varies the gearshift points as a function of the route the driver is taking and its specific profile. This means that the gears shift differently on uphill and downhill gradients than when driving on a flat, level surface. Driving uphill, for example, this function avoids the constant change of gears so typical of a conventional automatic transmission, the so-called pendulum gearshift with the gears constantly shifting up and down. When driving downhill, on the other hand, the M double clutch transmission keeps the lower gears in mesh longer than would otherwise be the case in order to capitalise on the brake power of the engine. And last but not least, the choice of gears is automatically adjusted to an uphill gradient in the automated mode."
So….could there be an issue with that part of the gearbox associated with GRADIENT DETECTION.
A BMW Master Tech should know all about this….
To me, taking the gearbox out seems a bit like taking a sledgehammer to crack an egg…….
Good luck, hope this helps…
David
David, thanks for the info. I think you may be right. Since originally writing my first description, the problem is now worse but something else I've noticed is that the car brakes on the gears quite a lot even when slowing on a level road. The gradient detection part not working correctly would explain a lot. Also as an aside, the car now slips in manual mode as well as auto/ efficiency and auto/sport.
The car came back after 2 days at BMW today. The gearbox problem is being referred to BMW technical Germany as they recognise the problem but cannot diagnose it. For reference the problem is getting worse, even standard gear changes are no longer smooth and engine braking on the gears in auto seems to be too harsh. I also complained about a "knocking noise" coming from the rear, especially noticeable when I go over something like a speed bump. The dealer has ordered a retrofit suspension kit which consists of new dampers, coils and bump stops for the rear and bump stops for the front. The kit is on back order and a 2 week wait at present. The cars booked in for about 2 weeks time, and I've even got a courtesy car this time!
The car came back from BMW on Wednesday having had the rear suspension changed and new software for the gearbox. Pleased to say both problems are fully sorted. No more "clunks" from the rear and the gearbox is good.
With everything fixed I can highly recommend the car, it's a cracking piece of kit, my likes are, excellent engine, good handling, the M1 and M2 pre set buttons for customising the settings, the head up display, seats are very comfy with excellent driving position. As I said with the problems fixed there is nothing I really dislike about the car. Being really critical, the steering can sometimes feel a little artificial, but I wouldn't describe it as poor.
With everything fixed I can highly recommend the car, it's a cracking piece of kit, my likes are, excellent engine, good handling, the M1 and M2 pre set buttons for customising the settings, the head up display, seats are very comfy with excellent driving position. As I said with the problems fixed there is nothing I really dislike about the car. Being really critical, the steering can sometimes feel a little artificial, but I wouldn't describe it as poor.
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