[randal63]

Hello everyone,
Ever since the cold days started (30 degrees Fahrenheit and below), I have had trouble taking off. When I start driving, the car jerks, it takes a fraction of a second. After a few minutes of driving, I stop and try to take off again. Everything's all right. I leave work, the engine is cold and the same thing again - one jerk. In warmer weather, the problem disappears. Does anyone have an idea for this? The car is under warranty. But I can't show it to the mechanics because when I arrive the car is warm and everything is fine.

QX30 2018

 

[p07r0457]

The DCT (transmission) in the QX30 is sensitive to temperature. Specifically, the DCT uses wet clutches, and the viscosity of the fluid plays a significant role in how "grippy" the clutch engagement is. The fluid used also changes volume with temperature. So when things are really cold, you'll get a bit of a jerky engagement. Once the fluid warms up the shift quality should normalize.

This has become a common characteristic of many modern transmissions. My Volvo uses a traditional slushbox (not DCT) and it also experiences an odd "first shift" on cold mornings. Again, that uses a fluid whose volume measurably changes between cold and operating temperatures.

Drive conservatively for the first few miles, until everything warms up to operating temperature. You'll be fine.

 

[randal63]

Thanks for the information. I will be able to sleep soundly without having nightmares.

 

[QX30Bob]

Hello everyone,
Ever since the cold days started (30 degrees Fahrenheit and below), I have had trouble taking off. When I start driving, the car jerks, it takes a fraction of a second. After a few minutes of driving, I stop and try to take off again. Everything's all right. I leave work, the engine is cold and the same thing again - one jerk. In warmer weather, the problem disappears. Does anyone have an idea for this? The car is under warranty. But I can't show it to the mechanics because when I arrive the car is warm and everything is fine.

QX30 2018

How many miles? 30K or more a transmission service will really smooth things out. Yes DCT is jumpy cold,its the price you pay for tight full throttle shifts. Make sure you use the DCT oil.

 

[randal63]

@QX30Bob
I have 17K miles.

 

[QX30Bob]

Too soon to change the fluid, its the nature of computer controlled transmissions. Lumpy when cold,low speed shifts. I think its 4yr 70k warranty so you have time,I wouldn't worry it sounds normal.