EGR Blocker

Most factory diesels were never built for Australian conditions. Add a loaded canopy, forty-degree heat and dirt roads, and the intake loses ground fast.
The EGR system is usually where trouble starts. It bleeds exhaust gas back into the intake to cool combustion and cut emissions. That works on a test bench. Out on the Birdsville Track, that gas carries fine soot into the manifold, where it mixes with crankcase oil vapour and builds into sludge that chokes airflow.