Motor trucks XC60 D3 AWD GT

Hello municipality, since recently I observe the following: I drive e.g. on the motorway with cruise control. All of a sudden the whole car starts with jerking, hpts. when it gets flatter after a mountain again or goes downhill. I tried it then without cruise control: if I go off the gas, then it takes a short time and then jerks again. What I noticed in the context: If I walk off the gas, it takes forever, until in the consumption indicator is 0.0. What could this be? Is the shut-off possible or does not work properly? Who knows this phenomenon? the erzbmw PS asks itself: after now about 83,000 km still satisfied, if one looks at various crack noises times. But on holiday now it is again beautifully purred … (and thanks to speed limitation and flat landscape and little traffic in Denmark I also had a 7 before the comma again 🙂 What I just can not get there here in the middle mountains!