These pre-Skyactiv diesels could have a couple of major problems. One was if the active regeneration of the DPF failed the engine sump would fill up with diesel leading to catastrophic engine failure. The other was that if the engine oil was not changed often enough, or if the old oil was siphoned out instead of drained, the residual slime in the sump could block the oil strainer leading to lack of oil pressure and engine failure.