Bloody hell its like a tractor
I see the service is due so pop the rocker cover off and have a look (use long life oil but every 10,000 miles)
Also collect the old oil and check for swarf
1900 rpm could be due to worn cams, egr flow or tandem pressure/injector seals leaking
Check the mvb 13 when the car is faulting not when warm
Read the measured value block 013 in the engine control unit and check the idle stabilisation. If the idle stabilisation of one or more cylinders is above +2.0 mg/H, remove the cylinder head cover and check whether the roller valve lever and the camshaft are worn. The clearance of the roll to the roller valve lever can be measured with a 0.15 mm feeler gauge (see arrow in photo 1). If there is sufficient clearance and no wear marks, the vehicle is correct. The high value in the measured value block 013 (>+2.0 mg/H) must have another cause. If there is no clearance between roll and roller valve lever (0.15 mm feeler gauge) and the roller valve lever is worn or the roller valve lever is broken, replace the camshaft and the tilting lever spindle. If the roller valve lever is broken, check whether other components are damaged.
pd head 1
Ill check mine from cold in the morning and log mvb 13