Auto gearbox surging

[Foffer]

My new 1.3 160 auto drives like a dream except for one thing and I wondered if others had noticed this.

when braking to a stop, then within a short time lifting your foot to creep forward the drive picks up suddenly and the car surges forward. Its feels to me as though pressing the brake pedal disengages the drive and then when you lift off the brake the drive re-engages and if this happens just after stopping it can be a bit harsh.

A bit difficult to describe, I hope I have made myself understood! It is not a big deal, just annoying when you try to drive as smooth as you can and it gets spoilt by this.

I would be interested to find out if others have noticed this or is my car not quite right?

[Qashowner]

Every auto car I have owned and driven will alway creep when drive is engaged, it will depend on tick over speed as to how fast the creep is. I have to 1.6 auto and that will move along at about 5mph on a flat road. I think the CVT box shows this off more that a 5,6 or 7 speed auto.

I hope that is what you are trying to describe

[Foffer]

Every auto car I have owned and driven will alway creep when drive is engaged, it will depend on tick over speed as to how fast the creep is. I have to 1.6 auto and that will move along at about 5mph on a flat road. I think the CVT box shows this off more that a 5,6 or 7 speed auto.

I hope that is what you are trying to describe

Thanks, I understand what you are saying but this isn't a creep, more of a jump! After the "jump" everything returns to normal. It feels like what you would expect if you've revved the engine in neutral, then engaged drive before the engine has returned to tickover

[calnorth]

Is this gearbox Xtronic? Meaning is there any software involved or is it without any electronic control.

I ask because I see that in some instances Nissan use Consult 3 to setup/configure such boxes. Theres an old thread here:

https://www.qashqaiforums.co.uk/viewtopic.php?t=1768

[gloucester]

The 1.3 isn't Xtronic

[calnorth]

Ok...so it has no electronic assistance?

[gloucester]

Well it's a 7-speed DCT auto transmission. In the 1.3 petrol 160 and the 1.5 diesel

The 1.7 diesel for some reason retains an Xtronic CTV gearbox.

[calnorth]

Yep...a computer controlled servo actuated gearbox...two clutches. Here's an old straylian on about the slow speed behaviour of DCT's. From ...straylia:

Goto 8 mins in Part 2

He's done a 3 part series on DCTs and they're not sh*t!....the boxes that is. So its electronics, software, electro mechanical interfaces and mechanical thingys...all controlled by +ve and -ve feedback. If its a Nissan problem get your battery changed first?



How they work:

[Foffer]

Very interesting videos thank you calnorth

It sounds like it could be my gearbox is caught out "dithering" under certain conditions at low speed. It is no big deal and hopefully I'll get used to it and be able to drive in a way to avoid this in future.

[calnorth]

Very interesting videos thank you calnorth

It sounds like it could be my gearbox is caught out "dithering" under certain conditions at low speed. It is no big deal and hopefully I'll get used to it and be able to drive in a way to avoid this in future.

My son has a 5 yr old AMG Merc C63 with a DCT box..so I asked him yesterday. I thought it would be perfect. It is very good on straight forward acceleration and as a muscle type car is as excepted. Its rather dithery etc on certain deceleration phases and at low speeds. Jumped at a pedestrian crossing causing people to yell at him....scared him too!

Merc have applied Firmware changes and attempted to charge for that. Not much improvement. Even big bucks don't hack it....it appears? For me its too complex, but every one to their own.

You’re essentially driving a car with a clutch take-up algorithm instead of a pedal.