A couple days ago my fwd 2016 s60 t5 started making a sort of fart noise whenever driving slow(20 mph or less). It did it even while I was sitting still car still on. I thought it was the bearings so those got replaced and I thought it was problem solved but after an hour or so it started up again. It almost feels like the abs is activating momentarily as it’ll make the “fart noise”(best way I can explain it) and kind of lurch the car when it does it. No lights have come on at all I just have no idea what it is