My 2004 VW Jetta TDI has a pulsing sensation at 2000 and 2500 rpm. It is a manual transmission. We’ve recently replaced the clutch/flywheel and the fuel filter. The problem has been progressively getting more common. Injectors, turbo, fuel filter problems?
IF I had a diesel engine, and it displayed those conditions, the first thing I would try is this.
Just follow the directions on the can.