135i DCT jerking on shift?

[ajlegrand95]

So let me start of by saying this is the first dual clutch car I have ever driver so I don't have anything to compare it to. That being said I want to put this out there to see if it's normal.

Bit of a back story -
This car was purchased very recently second hand. Its 2010 (MY11 with DCT) 135i E88. It has 3 months warranty from the dealer I purchased it from which is law in Australia so I can get anything that comes up fixed but only until FEB.

It's already been back as it was misfiring under decent throttle and would throw it into limp mode.
They said it was a coil and it's been replaced.
The car is now having long cranks and when really pushing it I can still feel a misfire and it has gone into limp mode twice since then, not as occuring as the first times but still happening. I've used the MHD app to read the current codes and it's got 36C9, 2BDE, 2BF0 which refers to fuel pressure (never tuned just used to read the codes because its free :P) So I'm taking it back again and saying I want the HPFP replaced.
The weirdest part of this is when it has gone into limp mode it's like there was a DSC fault as well. If I'm right the car threw up when it shifted from 2nd to 3rd under hard throttle and it comes up with DSC and FTM errors on screen and limp mode but no codes referrring to the DSC event.

NOW BACK TO THE MAIN POINT - sorry for the detour
The car is going back tuesday but it's got me thinking about how it shifts.

In normal drive mode shifting is nice and smooth.
In drive with sport button on the shifting is still relatively smooth but it doesn't have the same shifting noise as i'd expect.
I would describe it as more of a 'gap' in noise rather than a flutter. i tried to record it but it doens't come up too well

When using the manual mode with sport button pressed the car jolts with every shift. I know its snapping in even faster but i thought i'd still be smooth? Flipping the shifter across into S makes the shifts between gears even more rough. Is this how it's supposed to feel? I like to short shift and power away from the lights manually shifting at 3k rpm to just waft away from the rest of the traffic without making an obscene about of noise. So even at these low RPMs its pretty rough.

My other part of this is also the noise. I've listened to what youtube videos i can find of other DCT N55 engines and they all sound like they have the classic shift 'flutter noise' that is very distinctive with audi and VW engines.
I only get this flutter when i accelerate super lightly and hold first gear untill about 5k RPM and then it flutters to second. If I'm accelerating at any other rate its more of a sudden gap of exhaust noise then a 'pop' as it snaps back into the next gear.

Could this all be caused by a bad fuel pump or is my transmission on the way out too?

Sorry for the long post but I'm so nervous I've bought a time bomb and don't have long to weed out any hiding problems!

[mfindigital]

Fuel pump failing sounds totally normal. That shift kick also sounds totally normal in sport mode. Try driving an SMG equipped car one day, you'll think your car is Rolls Royce smooth after.

The pumps on these cars go out all the time. Basically all of these cars are time bombs. There are 5 or 6 things that are going to break on all of them. I've had all of the issues besides my HPFP going out, but that seems to be just around the corner.

FYI on slow starts, alot of people will say coils and plugs, others will say hpfp, but mine was caused by the starter. It took almost two years to die on me, but it did. I have seen very, very, very few people have long cranks solved by coils and plugs, and they aren't that cheap, so definitely get things tested before spending a few hundred dollars based on suggestions here.

[BimmerAg]

Maybe a video of the shift sound would be more helpful than trying to describe it with words. Generally with my DCT, shifts get firmer in manual mode, with the lever moved over, or with the port button pressed. With all 3, mine gives a little push in the back with each shift as it snaps up to the next gear. Very smooth in normal driving.

As for the sound, I can get mine to do different things based on how much throttle I give, and of course the transmission and sport button settings. (Now I'll proceed to decribe how my car sounds with words after asking you to post a video lol ) Usually, with the transmission in sport mode, I get a bit of a pop sound on upshifts. With the sport button pressed, I'll get the classic DCT "burp" or flutter sound under light to medium acceleration, or more of a "pop" under heavier acceleration.

Sounds to me like your transmission is generally behaving as it should, but maybe see how it feels and sounds after getting your fuel pump replaced and report back.

[dtla1]

The TPMS and DSC Failure codes are odd. Maybe ask to see if the battery has ever been replaced, could be time.

Also, wouldn't hurt to ask for the adaptation on the DCT transmission be reset, might fix any weird shifting issues.

[Kheadley]

When you're in sport and shift youre going to get hard shifts. Ever slam gears quickly on a manual? Feels the same but faster. When I'm in drive it's smooth but when I step on it I get thrown in my seat because it shifts so fast.

[ajlegrand95]

UPDATE:

So it's been back at the shop for a few days. I called for an update and they said the car was sent to BMW for diagnostics and they've come back saying it needs a new DME.

Could a failing DME cause these issues with misfires and the DCT/FTM errors on the screen?

I still think the HPFP is on its way out so because of the long ass cranking.

[Windy5000]

Originally Posted by dtla1

Also, wouldn't hurt to ask for the adaptation on the DCT transmission be reset, might fix any weird shifting issues.

This.

[Happy Jose]

Originally Posted by ajlegrand95

UPDATE:

So it's been back at the shop for a few days. I called for an update and they said the car was sent to BMW for diagnostics and they've come back saying it needs a new DME.

Could a failing DME cause these issues with misfires and the DCT/FTM errors on the screen?

I still think the HPFP is on its way out so because of the long ass cranking.

You need to do some research. There are companies that can reprogram the DME. It isn't difficult to remove. The fuel pump can be easily checked by measuring the fuel pressure. Any shop can do this.

FTM error might be a bad TPMS on the rim. I'm not sure, but I believe the DCT has an electronic link to the DME. In any case, I see tons of videos and discussions on these issue. You should start reading and watching this stuff.

[dtla1]

Originally Posted by ajlegrand95

UPDATE:

So it's been back at the shop for a few days. I called for an update and they said the car was sent to BMW for diagnostics and they've come back saying it needs a new DME.

Could a failing DME cause these issues with misfires and the DCT/FTM errors on the screen?

I still think the HPFP is on its way out so because of the long ass cranking.

I know you have a code for pressure too low, but a long crank can also be a dying starter, the cable to the starter might be fraying or the ground strap could be quite corroded. All pretty common. Both of the cable issues can be diagnosed visually, and without taking much/anything apart.

[mfindigital]

Originally Posted by dtla1

I know you have a code for pressure too low, but a long crank can also be a dying starter, the cable to the starter might be fraying or the ground strap could be quite corroded. All pretty common. Both of the cable issues can be diagnosed visually, and without taking much/anything apart.

Mine was the starter, just fyi. Alot of people will insist on the fraying wire, but best to check both out.

What's the reason for a new DME? That seems extreme and excessive.

[dtla1]

Originally Posted by mfindigital

Mine was the starter, just fyi. Alot of people will insist on the fraying wire, but best to check both out.

What's the reason for a new DME? That seems extreme and excessive.

Agreed that it's best to check both, the frying wire is just an easier thing to rule out first since the starter is buried pretty deep back there if you want to get to it for testing.