Home Repair and Service Manual High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine

High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine

0
This article is AI free. It contains original content, and was researched and written by our own staff at the BMW Repair Guide. For more information on our AI Free Zone, please click here.
Affiliate link disclosure – The BMW Repair Guide uses affiliate links in their site. For more information on affiliate links, please click here.

High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine

This article gives step-by-step instructions on removing and replacing the high-pressure fuel pump in the BMW B46/B48 4-cylinder turbocharged engine.
Not sure which engine you have in your BMW? Use our engine finder tool to easily identify it!
Possible Symptoms: Engine won't start, engine stalls, lack of power when accelerator depressed
This repair can be used on the following BMW models:
Expert level repair.

Step 1 - Purchase Parts

You will need the following parts and supplies to perform this repair.

High Pressure Fuel Pump

Once again...we are going to preach about purchasing cheap fuel pumps from Amazon and Ebay with manufacturer names you cannot even pronounce. Yea...you get our point. Only...and we mean only install a Genuine BMW factory high pressure fuel pump in your vehicle. Cheap pumps will fail, and can seriously damage your engine. This is the same factory high pressure fuel pump that would be installed at the delaership.

Fuel Pump Gasket

When installing a new high pressure fuel pump in your engine, always replace the profile gasket. This will ensure you are leak free after the repair.

Depth Gauge

Excellent automotive depth gauge for measuring smaller holes and slots. Hardened steel base.

Step 2 - Repair Procedure

Unless otherwise noted, all vehicle repair step images in this article are copyrighted, and used courtesy of BMW of North America, Inc. .
Warning
Disconnect battery.

  • You must disconnect the battery before starting this repair. Not disconnecting the battery may cause catastrophic damage to the engine.

1. Disconnect the battery.
High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine
Click to enlarge image

- Remove right trim panel from side of trunk (1).

View part diagram for this step
Pro Tip

Tape a rag around the intelligent battery sensor in the next step to protect it from being damaged. A damaged IBS will cause error codes and electrical malfunctions!

High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine
Click to enlarge image

- Disconnect the negative (1) terminal.

- WARNING. Take extreme care not to damage the intelligent battery sensor (2) attached to the negative cable.

You must remove the ignition coils before continuing with this repair!

Please see our article Ignition Coil Replacement - B46 Turbo 4-Cylinder Engine for instructions on removing the ignition coils.

2. Remove the fuel lines.
High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine
Click to enlarge image

- Locate the fuel hose/fuel pump feed line quick disconnect (1).

- Remove the plastic safety clip.

- Push the release collar (2) in direction of arrow then pull the lines apart. Have a rag ready to catch any fuel that spills out.

- Loosen the mounting screw (3).

View part diagram for this step
High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine
Click to enlarge image

- Loosen the union nut that attached the fuel delivery line (2) to the high pressure fuel pump (1).

- Remove the fuel delivery line from the engine.

View part diagram for this step
High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine
Click to enlarge image

- Place rags under the high pressure fuel line to catch any fuel that escapes in the next step.

- Loosen union nuts (2) from fuel pump and fuel rail and allow fuel to drain out.

View part diagram for this step
High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine
Click to enlarge image

- Completely release the union nuts and remove the high pressure fuel line from the engine compartment.

View part diagram for this step
3. Remove the high pressure fuel pump.
High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine
Click to enlarge image

- Unplug the high pressure fuel pump (1).

- Slowly remove torx mounting bolts (arrows), carefully alternating turns between the two.

- Grasp the fuel pump and remove from engine.

View part diagram for this step
4. Installing a new high pressure fuel pump.
High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine
Click to enlarge image

- It is important that the high pressure fuel pump camshaft is at its lowest point before installing a new fuel pump. The easiest way to achieve this is with a simple depth gauge (see tool list above).

High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine
Click to enlarge image

- Install the depth gauge into the high pressure pump cavity as shown in the image. The ruler must be positioned on top of the camshaft at the bottom of the cavity.

High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine
Click to enlarge image

- Remove the cap from the vibration damper (harmonic balancer) on the lower front of the engine (see part diagram link below). Using a socket and long breaker bar, slowly turn the engine CLOCKWISE until the high pressure pump camshaft has reached its lowest position.

View part diagram for this step
High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine
Click to enlarge image

- Install a new fuel pump gasket.

View part diagram for this step
High Pressure Fuel Pump Repair – BMW B46 Turbo 4 Cylinder Engine
Click to enlarge image

- Install the new fuel pump.

- Tighten the mounting bolts (arrows) in 90 degree increments until snug. Torque bolts to 12 Nm (8.8 ft-lb).

View part diagram for this step
4. Final installation torque values.

- High pressure fuel line union nuts from pump to fuel rail: 33 Nm (24 ft-lb)

- Fuel delivery line union nut from pump to quick disconnect: 31 Nm (22.8 ft-lb)

Please refer to ignition repair article for final reassembly

Ignition Coil Replacement - B46 Turbo 4-Cylinder Engine

r-13-51
Copyright BMW Repair Guide 2024 - All Rights Reserved