The most common cause of performance loss in late-model diesel engines is clogging of the intake manifold with oil vapour build-up. We have seen the air supply pipe practically closed off by oil sludge build-up. Thorough cleaning of the turbo crossover pipe and intake manifold should be done every 50,000km. Oil vapours on diesel engines are introduced into the intake air stream by a breather hose that vents the crankcase next to the oil fill cap. Vapours build up and eventually choke off the intake air supply.
- Ecu remap