Fuel System - Diesel Fuel Contamination Repair Guideline

SI B 13 11 10
Fuel System

August 2010
Technical Service

SUBJECT
M57Y - Diesel Fuel Contaminated with Gasoline; Repair Guidelines

MODEL
E90 335d with M57Y
E70 X5 xDrive35d with M57Y

SITUATION
BMW Advanced Diesel vehicles are equipped with a fuel-filler neck that incorporates a misfueling protection system, to prevent gasoline from being mistakenly pumped into the vehicle. If the vehicle is operated with gasoline in the fuel tank, internal engine damage, fuel delivery and emission control systems failure will occur.

Only fuel nozzles with the recommended diameter for diesel passenger vehicles can be inserted into the filler neck. Most diesel fuel stations have fuel nozzles with the recommended diameter fitted to their passenger vehicle diesel fuel pumps. But if the filler-neck misfueling protection system has been disabled, or the incorrect fuel nozzle has been installed on the gasoline fuel pump, the vehicle's diesel fuel system may be contaminated with gasoline.

If the diesel fuel system has been contaminated with gasoline, follow the repair guidelines below:

1. The vehicle has been misfueled, but the engine has not been started yet:

^ Drain the fuel tank completely and flush it with clean diesel fuel. No further repairs are needed.

2. The vehicle has been driven with gasoline contamination for a short time (less than 5 miles):

^ Drain the fuel tank completely and flush it with clean diesel fuel. Drain and clean all fuel lines. Replace the fuel filter and the injection High-pressure Pump.

^ If the gasoline volume exceeds 50% of the tank's capacity, replace the Diesel Particulate Filter (DPF) due to possible internal overheating.

3. The vehicle has been driven with gasoline contamination for more than 5 miles:

^ Replace the fuel tank, all fuel lines (low and high-pressure sides), fuel filter, High-pressure Pump, injection rail and all injectors.

^ Also replace the Diesel Oxidation Catalyst (DOC) and the Diesel Particulate Filter (DPF) due to internal overheating damage.

WARRANTY INFORMATION
Any repair to the M57Y engine, its fuel supply system or the emission control system caused by misfueling and gasoline contamination is not covered under the terms of the BMW New Vehicle Limited Warranty.