Fuel Pressure Test – BMW B46/B48 Turbo 4-cylinder Engine

August 27, 2023

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Fuel Pressure Test – BMW B46/B48 Turbo 4-cylinder Engine

This repair gives step-by-step instructions on performing a low-pressure fuel test on the B46/B48 4-cylinder turbocharged engine. A low-pressure fuel test is necessary when trying to diagnose a faulty fuel pump or clogged fuel filter.

Not sure which engine you have in your BMW? Use our engine finder tool to easily identify it!

Possible Symptoms: Not applicable for this repair.

This repair can be used on the following BMW models:

2013

225i Active Tourer, Cooper S 3 doors,

2014

220i Active Tourer, 220i Gran Tourer, 225i Active Tourer, 225iX Active Tourer, 320i Touring, 320iX Touring, 330i Touring, 730Li Sedan, 730i Sedan, Cooper S 3 doors, Cooper S 5 doors, Cooper S Clubman, Cooper S Convertible, JCW 3 doors, X1 20Li SUV, X1 20LiX SUV, X1 20i SUV, X1 20iX SUV, X1 25LiX SUV, X1 25iX SUV, X1 28i SUV, X1 28iX SUV,

2015

2016

120i 3 doors, 120i 5 doors, 120i Sedan, 125i 3 doors, 125i 5 doors, 125i Sedan, 220i Active Tourer, 220i Convertible, 220i Coupe, 220i Gran Tourer, 225i Active Tourer, 225iX Active Tourer, 230i Convertible, 230i Coupe, 230iX Convertible, 230iX Coupe, 320Li Sedan, 320LiX Sedan, 320i Gran Turismo, 320i Touring, 320iX Gran Turismo, 320iX Touring, 330Li Sedan, 330LiX Sedan, 330e Sedan, 330i Gran Turismo, 330i Sedan, 330i Touring, 330iX Gran Turismo, 330iX Sedan, 330iX Touring, 420i Convertible, 420i Coupe, 420i Gran Coupe, 420iX Coupe, 420iX Gran Coupe, 430i Convertible, 430i Coupe, 430i Gran Coupe, 430iX Convertible, 430iX Coupe, 430iX Gran Coupe, 520i 1.6 Sedan, 520i Sedan, 520i Touring, 525Li Sedan, 528Li Sedan, 530Le Sedan, 530Li Sedan, 530LiX Sedan, 530e Sedan, 530eX Sedan, 530i Sedan, 530i Touring, 530iX Sedan, 530iX Touring, 630i Gran Turismo, 730Li Sedan, 730i Sedan, 740Le Sedan, 740LeX Sedan, 740e Sedan, 740eX Sedan, Cooper S ALL4 Clubman, Cooper S ALL4 Countryman, Cooper S 3 doors, Cooper S 5 doors, Cooper S Clubman, Cooper S Convertible, Cooper S Countryman, JCW ALL4 Clubman, JCW ALL4 Countryman, JCW 3 doors, JCW Convertible, X1 20Li SUV, X1 20LiX SUV, X1 20i SUV, X1 20iX SUV, X1 25LiX SUV, X1 25iX SUV, X1 28i SUV, X1 28iX SUV, X2 20i SAC, X2 28iX SAC, X3 20i 1.6 SUV, X3 20i SUV, X3 20iX (TR51) SUV, X3 30iX (TR91) SUV, X3 30iX (TR92) SUV, X3 30iX SUV,

2017

120i 3 doors, 120i 5 doors, 120i Sedan, 125i 3 doors, 125i 5 doors, 125i Sedan, 220i Active Tourer, 220i Convertible, 220i Coupe, 220i Gran Tourer, 225i Active Tourer, 225iX Active Tourer, 230i Convertible, 230i Coupe, 230iX Convertible, 230iX Coupe, 320Li Sedan, 320LiX Sedan, 320i Gran Turismo, 320i Sedan, 320i Touring, 320iX Gran Turismo, 320iX Touring, 330Li Sedan, 330LiX Sedan, 330e Sedan, 330i Gran Turismo, 330i Sedan, 330i Touring, 330iX Gran Turismo, 330iX Sedan, 330iX Touring, 420i Convertible, 420i Coupe, 420i Gran Coupe, 420iX Coupe, 420iX Gran Coupe, 430i Convertible, 430i Coupe, 430i Gran Coupe, 430iX Convertible, 430iX Coupe, 430iX Gran Coupe, 520i 1.6 Sedan, 520i Sedan, 520i Touring, 525Li Sedan, 528Li Sedan, 530Le Sedan, 530Li Sedan, 530LiX Sedan, 530e Sedan, 530eX Sedan, 530i Sedan, 530i Touring, 530iX Sedan, 530iX Touring, 630i Gran Turismo, 730Li Sedan, 730i Sedan, 740Le Sedan, 740LeX Sedan, 740e Sedan, 740eX Sedan, Cooper S ALL4 Clubman, Cooper S ALL4 Countryman, Cooper S 3 doors, Cooper S 5 doors, Cooper S Clubman, Cooper S Convertible, Cooper S Countryman, JCW ALL4 Clubman, JCW ALL4 Countryman, JCW 3 doors, JCW Convertible, X1 20Li SUV, X1 20LiX SUV, X1 20i SUV, X1 20iX SUV, X1 25LiX SUV, X1 25iX SUV, X1 28i SUV, X1 28iX SUV, X2 20i SAC, X2 20iX SAC, X2 25iX SAC, X2 28i SAC, X2 28iX SAC, X2 M35iX SAC, X3 20i (TR12) SUV, X3 20i (TR16) SUV, X3 20i 1.6 SUV, X3 20i SUV, X3 20iX (TR51) SUV, X3 20iX (TR52) SUV, X3 20iX (TR55) SUV, X3 20iX (TR56) SUV, X3 25iX SUV, X3 28iX SUV, X3 30i SUV, X3 30iX (TR91) SUV, X3 30iX (TR92) SUV, X3 30iX (TR95) SUV, X3 30iX (TR96) SUV, X3 30iX SUV, X4 20iX SAC, X4 30iX SAC, Z4 20i Roadster, Z4 30i Roadster,

2018

120i 3 doors, 120i 5 doors, 120i Sedan, 125i 3 doors, 125i 5 doors, 125i Sedan, 220i Active Tourer, 220i Convertible, 220i Coupe, 220i Gran Tourer, 225i Active Tourer, 225iX Active Tourer, 228iX Gran Coupe, 230i Convertible, 230i Coupe, 230iX Convertible, 230iX Coupe, 320Li Sedan, 320LiX Sedan, 320i 1.6 Sedan, 320i Gran Turismo, 320i Sedan, 320i Touring, 320iX Gran Turismo, 320iX Sedan, 320iX Touring, 325Li Sedan, 325LiX Sedan, 325i Sedan, 330Li Sedan, 330LiX Sedan, 330e Sedan, 330i Gran Turismo, 330i Sedan, 330i Touring, 330iX Gran Turismo, 330iX Sedan, 330iX Touring, 420i Convertible, 420i Coupe, 420i Gran Coupe, 420iX Coupe, 420iX Gran Coupe, 430i Convertible, 430i Coupe, 430i Gran Coupe, 430iX Convertible, 430iX Coupe, 430iX Gran Coupe, 520i 1.6 Sedan, 520i Sedan, 520i Touring, 525Li Sedan, 530Le Sedan, 530Li Sedan, 530LiX Sedan, 530e Sedan, 530eX Sedan, 530i Sedan, 530i Touring, 530iX Sedan, 530iX Touring, 630i Gran Turismo, 730Li Sedan, 730i Sedan, 740Le Sedan, 740LeX Sedan, 740e Sedan, 740eX Sedan, Cooper S ALL4 Clubman, Cooper S ALL4 Countryman, Cooper S 3 doors, Cooper S 5 doors, Cooper S Clubman, Cooper S Convertible, Cooper S Countryman, JCW ALL4 Clubman, JCW ALL4 Countryman, JCW 3 doors, JCW Convertible, M135iX 5 doors, M235iX Gran Coupe, X1 20Li SUV, X1 20LiX SUV, X1 20i SUV, X1 20iX SUV, X1 25Li SUV, X1 25LiX SUV, X1 25iX SUV, X1 28i SUV, X1 28iX SUV, X2 20i SAC, X2 20iX SAC, X2 25i SAC, X2 25iX SAC, X2 28i SAC, X2 28iX SAC, X2 M35iX SAC, X3 20i (TR12) SUV, X3 20i (TR16) SUV, X3 20i 1.6 SUV, X3 20i SUV, X3 20iX (TR51) SUV, X3 20iX (TR52) SUV, X3 20iX (TR55) SUV, X3 20iX (TR56) SUV, X3 20iX SUV, X3 25iX SUV, X3 28iX SUV, X3 30eX SUV, X3 30i SUV, X3 30iX (TR91) SUV, X3 30iX (TR92) SUV, X3 30iX (TR95) SUV, X3 30iX (TR96) SUV, X3 30iX SUV, X4 20iX SAC, X4 30iX SAC, X5 30iX SUV, X6 30iX SAC, Z4 20i Roadster, Z4 30i Roadster,

2019

120i 3 doors, 120i 5 doors, 120i Sedan, 125i 3 doors, 125i 5 doors, 220i Active Tourer, 220i Convertible, 220i Coupe, 220i Gran Tourer, 225i Active Tourer, 225iX Active Tourer, 228iX Gran Coupe, 230i Convertible, 230i Coupe, 230iX Convertible, 230iX Coupe, 320Li Sedan, 320LiX Sedan, 320i 1.6 Sedan, 320i Gran Turismo, 320i Sedan, 320i Touring, 320iX Gran Turismo, 320iX Sedan, 320iX Touring, 325Li Sedan, 325LiX Sedan, 325i Sedan, 330LiX Sedan, 330e Sedan, 330i Gran Turismo, 330i Sedan, 330i Touring, 330iX Gran Turismo, 330iX Sedan, 330iX Touring, 420i Convertible, 420i Coupe, 420i Gran Coupe, 420iX Coupe, 420iX Gran Coupe, 430i Convertible, 430i Coupe, 430i Gran Coupe, 430iX Convertible, 430iX Coupe, 430iX Gran Coupe, 520i 1.6 Sedan, 520i Sedan, 520i Touring, 525Li Sedan, 530Le Sedan, 530Li Sedan, 530LiX Sedan, 530e Sedan, 530eX Sedan, 530i Sedan, 530i Touring, 530iX Sedan, 530iX Touring, 630i Gran Turismo, 730Li Sedan, 730i Sedan, 740Le Sedan, 740LeX Sedan, 740e Sedan, 740eX Sedan, Cooper S ALL4 Clubman, Cooper S ALL4 Countryman, Cooper S 3 doors, Cooper S 5 doors, Cooper S Clubman, Cooper S Convertible, Cooper S Countryman, JCW ALL4 Clubman, JCW ALL4 Countryman, JCW 3 doors, JCW Convertible, M135iX 5 doors, M235iX Gran Coupe, X1 20Li SUV, X1 20LiX SUV, X1 20i SUV, X1 20iX SUV, X1 25Li SUV, X1 25LiX SUV, X1 25iX SUV, X1 28i SUV, X1 28iX SUV, X2 20i SAC, X2 20iX SAC, X2 25i SAC, X2 25iX SAC, X2 28i SAC, X2 28iX SAC, X2 M35iX SAC, X3 20i (TR12) SUV, X3 20i (TR16) SUV, X3 20i 1.6 SUV, X3 20i SUV, X3 20iX (TR51) SUV, X3 20iX (TR52) SUV, X3 20iX (TR55) SUV, X3 20iX (TR56) SUV, X3 20iX SUV, X3 25iX SUV, X3 28iX SUV, X3 30eX SUV, X3 30i SUV, X3 30iX (TR91) SUV, X3 30iX (TR92) SUV, X3 30iX (TR95) SUV, X3 30iX (TR96) SUV, X3 30iX SUV, X4 20iX SAC, X4 30iX SAC, X5 30iX SUV, X6 30iX SAC, Z4 20i Roadster, Z4 30i Roadster,

2020

320i Sedan, 330e Sedan, 520i Sedan, 630i Gran Turismo, 730Li Sedan, 730i Sedan, X1 20i SUV, X1 20iX SUV,

Intermediate level repair.

Step 1 - Purchase Parts

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

Fuel Pressure Test Gauge - Quick Disconnect

Checking the fuel pressure in your BMW or MINI is a necessity for diagnosing faulty fuel pumps and clogged fuel filters. This easy-to-use kit quickly snaps onto you quick disconnect giving you accurate fuel pressure readings up to 7 bar (100 psi).

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

Fuel spillage!

A small amount of fuel will be discharged during this procedure. Have rags ready

Technical Information

You must have a fuel pressure test kit to perform this repair. Please see our special tools block above to order one.

1. Test fuel pressure.

Fuel Pressure Test – BMW B46/B48 Turbo 4-cylinder Engine

Click to enlarge image

- Locate the black plastic cover (1) on the left rear of engine next to the strut tower.

Click to enlarge image

- The fuel line quick disconnect (1) is located under the cover. Use a small pick to remove the gray plastic safety clip.

View part diagram for this step

Click to enlarge image

- Push the release collar (1) in (direction of arrow).

- Pull the quick disconnect apart releasing the fuel hose from the fuel line. Have rags ready to catch any fuel that escapes.

View part diagram for this step

Click to enlarge image

- Attach (A) of fuel test adapter to fuel hose, (B) to fuel line, and (C) to pressure guage.

- Start vehicle (if possible) and read pressure. If vehicle won't run, read pressure level while a helper attempts to start the vehicle.

Notes on fuel pressure for the B46/B48 engine:

This procedure measures the low pressure side of the system that feeds the high pressure fuel pump.

A low pressure (or no pressure reading) may signify a faulty low pressure fuel pump or clogged fuel filter.