Replacing Dt466e Injectors requires attention to detail to prevent engine damage. Injector O-rings should always be replaced with new ones during injector removal. These O-rings are essentially single-use components, especially after prolonged exposure to heat and pressure. Reusing them, particularly after years of service, risks leaks due to deformation and potential damage during removal. This is crucial because the high-pressure oil pump (HPOP) operates at 3000 PSI.
Another critical step is ensuring all oil is cleared from the cylinders before reinstalling the injectors. While fuel might seep past the piston rings into the oil pan, oil will pool, leading to catastrophic engine damage upon startup. Because the HPOP is mechanically driven and always has some degree of flow due to the injection pressure regulator (IPR), even cranking the engine briefly with the injectors out will pump oil into the cylinders. While a couple of rotations might be acceptable, observe for oil flowing back into the injector bores if the drain plug hasn’t been removed.
The recommended practice after injector installation is to manually rotate the engine four full turns. This laborious process allows you to physically feel for any hydraulic lock caused by oil in the cylinders and permits the pressurized oil to escape past the piston rings and into the exhaust manifold. Using the starter is strongly discouraged due to the risk of forcing oil into the cylinders too quickly.
Finally, an oil change is mandatory after this procedure. Whether or not to replace the bearings depends on the engine’s overall condition. Consider bearing replacement if a full rebuild/in-frame overhaul is planned or if there are existing signs of wear, such as low hot oil pressure or unusual engine noise.
