I have a 2006 VW tdi 1.9l Jetta. Engine runs AMAZING in the summer and no problems!! In the winter. When it gets cold and if I ride on the rumble strips on the road the engine hesitates or jerks. It also now when I go above 2000 rpm’s will do the same thing! Replaces the fuel filter about 10,000 miles ago. Could that be the problem??