Service Action: N14 Engine Retrofit Turbocharger Engine Oil Supply Line Heat Shield. After switching off the engine, the heat radiating from the turbocharger may cause the engine oil to solidify in the oil supply line to the turbocharger. This can lead to a restriction in the oil supply line, resulting in damage to the turbocharger bearings. CAUSE Close proximity of the turbocharger engine oil supply line and the turbocharger