Fuel Pressure Test – BMW N52 6 Cylinder Engine

November 11, 2023

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Fuel Pressure Test – BMW N52 6 Cylinder Engine

Not supplying the correct pressurized fuel to your injectors can cause your BMW to run rough. Even small deviations in fuel pressure can cause severe performance issues. If you suspect your BMW's engine isn't getting enough fuel, then we suggest running a fuel pressure test to diagnose the issue. This article gives step-by-step instructions on performing a fuel pressure test in the N52 inline six-cylinder engine.

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

Possible Symptoms: Rough idle, lack of power, engine stalls

This repair can be used on the following BMW models:

2004

325i Sedan, 325i Touring, 325xi Sedan, 328i Touring, 330i Sedan, 330i Touring, 330xi Touring, 523i Sedan, 523i Touring, 525i Sedan, 525i Touring, 525xi Sedan, 525xi Touring, 530i Sedan, 530i Touring, 530xi Sedan, 530xi Touring, 630i Convertible, 630i Coupe, 730Li Sedan, 730i Sedan, Z4 2.5si Roadster, Z4 3.0i Roadster, Z4 3.0si Roadster,

2005

130i 5 doors, 323i Sedan, 323i Touring, 325i Coupe, 325i Sedan, 325i Touring, 325xi Coupe, 325xi Sedan, 325xi Touring, 328i Convertible, 328i Coupe, 330i Convertible, 330i Coupe, 330i Sedan, 330i Touring, 330xi Coupe, 330xi Sedan, 330xi Touring, 523i Sedan, 523i Touring, 525i Sedan, 525i Touring, 525xi Sedan, 525xi Touring, 528i Sedan, 528xi Sedan, 530i Sedan, 530i Touring, 530xi Sedan, 530xi Touring, 630i Convertible, 630i Coupe, 730Li Sedan, 730i Sedan, Z4 2.5si Roadster, Z4 3.0i Roadster, Z4 3.0si Coupe, Z4 3.0si Roadster,

2006

128i Convertible, 128i Coupe, 130i 3 doors, 130i 5 doors, 323i Coupe, 323i Sedan, 323i Touring, 325i Convertible, 325i Coupe, 325i Sedan, 325i Touring, 325xi Coupe, 325xi Sedan, 325xi Touring, 328i Convertible, 328i Coupe, 328i Sedan, 328i Touring, 328xi Coupe, 328xi Sedan, 328xi Touring, 330i Convertible, 330i Coupe, 330i Sedan, 330i Touring, 330xi Coupe, 330xi Sedan, 330xi Touring, 523Li Sedan, 523i Sedan, 523i Touring, 525Li Sedan, 525i Sedan, 525i Touring, 525xi Sedan, 525xi Touring, 528i Sedan, 528xi Sedan, 530Li Sedan, 530i Sedan, 530i Touring, 530xi Sedan, 530xi Touring, 630i Convertible, 630i Coupe, 730Li Sedan, 730i Sedan, X3 2.5si SUV, X3 3.0i SUV, X3 3.0si SUV, X5 3.0si SUV, Z4 2.5si Roadster, Z4 3.0i Roadster, Z4 3.0si Coupe, Z4 3.0si Roadster,

2007

125i Convertible, 125i Coupe, 128i Convertible, 128i Coupe, 130i 3 doors, 130i 5 doors, 323i Convertible, 323i Coupe, 323i Sedan, 323i Touring, 325i Convertible, 325i Coupe, 325i Sedan, 325i Touring, 325xi Coupe, 328i Convertible, 328i Coupe, 328i Sedan, 328i Touring, 328xi Coupe, 328xi Sedan, 328xi Touring, 330i Convertible, 330i Coupe, 330i Sedan, 330i Touring, 330xi Coupe, 330xi Touring, 523Li Sedan, 523i Sedan, 523i Touring, 525Li Sedan, 525i Sedan, 525i Touring, 525xi Sedan, 525xi Touring, 528i Sedan, 528xi Sedan, 530Li Sedan, 530i Sedan, 530i Touring, 530xi Sedan, 530xi Touring, 630i Convertible, 630i Coupe, 730Li Sedan, 730i Sedan, X3 2.5si SUV, X3 3.0i SUV, X3 3.0si SUV, X5 3.0si SUV, Z4 2.5si Roadster, Z4 3.0i Roadster, Z4 3.0si Coupe, Z4 3.0si Roadster,

2008

125i Convertible, 125i Coupe, 128i Convertible, 128i Coupe, 130i 3 doors, 130i 5 doors, 323i Convertible, 323i Coupe, 323i Sedan, 323i Touring, 325i Convertible, 325i Coupe, 325i Sedan, 325i Touring, 325xi Coupe, 325xi Sedan, 325xi Touring, 328i Convertible, 328i Coupe, 328i Sedan, 328i Touring, 328xi Coupe, 328xi Sedan, 328xi Touring, 330i Convertible, 330i Coupe, 330i Sedan, 330i Touring, 523Li Sedan, 523i Sedan, 523i Touring, 525Li Sedan, 525i Sedan, 525i Touring, 528i Sedan, 528xi Sedan, 530Li Sedan, 530i Sedan, 530i Touring, 530xi Sedan, 530xi Touring, 630i Convertible, 630i Coupe, 730Li Sedan, 730i Sedan, X1 25iX SUV, X3 2.5si SUV, X3 3.0i SUV, X3 3.0si SUV, X5 3.0si SUV, Z4 2.5si Roadster, Z4 23i Roadster, Z4 3.0i Roadster, Z4 3.0si Coupe, Z4 3.0si Roadster, Z4 30i Roadster,

2009

125i Convertible, 125i Coupe, 128i Convertible, 128i Coupe, 130i 3 doors, 130i 5 doors, 323i Convertible, 323i Coupe, 323i Sedan, 323i Touring, 325i Convertible, 325i Coupe, 325i Sedan, 325i Touring, 325xi Coupe, 325xi Sedan, 325xi Touring, 328i Convertible, 328i Coupe, 328i Sedan, 328i Touring, 328xi Coupe, 328xi Sedan, 328xi Touring, 330i Convertible, 330i Coupe, 330i Sedan, 330i Touring, 520Li Sedan, 523Li Sedan, 523i Sedan, 523i Touring, 525Li Sedan, 525i Sedan, 525i Touring, 528Li Sedan, 528i Sedan, 528xi Sedan, 530Li Sedan, 530i Sedan, 530i Touring, 530xi Sedan, 530xi Touring, 630i Convertible, 630i Coupe, 730Li Sedan, 730i Sedan, X1 25iX SUV, X3 2.5si SUV, X3 28iX SUV, X3 3.0i SUV, X3 3.0si SUV, X5 3.0si SUV, Z4 23i Roadster, Z4 30i Roadster,

2010

125i Convertible, 125i Coupe, 128i Convertible, 128i Coupe, 130i 3 doors, 130i 5 doors, 323i Convertible, 323i Coupe, 323i Sedan, 323i Touring, 325i Convertible, 325i Coupe, 325i Sedan, 325i Touring, 325xi Coupe, 325xi Sedan, 325xi Touring, 328i Convertible, 328i Coupe, 328i Sedan, 328i Touring, 328xi Coupe, 328xi Sedan, 328xi Touring, 330i Convertible, 330i Coupe, 330i Sedan, 520Li Sedan, 523Li Sedan, 523i Sedan, 523i Touring, 525Li Sedan, 525i Touring, 528Li Sedan, 528i Sedan, 530Li Sedan, 530i Sedan, 530i Touring, 530xi Touring, 630i Convertible, 630i Coupe, 730Li Sedan, 730i Sedan, X1 25iX SUV, X3 2.5si SUV, X3 28iX SUV, X3 3.0i SUV, X3 3.0si SUV, X5 3.0si SUV, Z4 23i Roadster, Z4 30i Roadster,

2011

125i Convertible, 125i Coupe, 128i Convertible, 128i Coupe, 130i 3 doors, 130i 5 doors, 323i Convertible, 323i Coupe, 323i Sedan, 323i Touring, 325i Convertible, 325i Coupe, 325i Sedan, 325xi Coupe, 325xi Sedan, 325xi Touring, 328i Convertible, 328i Coupe, 328i Sedan, 328i Touring, 328xi Coupe, 328xi Sedan, 328xi Touring, 330i Convertible, 330i Coupe, 330i Sedan, 520Li Sedan, 523Li Sedan, 523i Sedan, 523i Touring, 528Li Sedan, 528i Sedan, 530Li Sedan, 530i Sedan, 530i Touring, 730Li Sedan, 730i Sedan, X1 25iX SUV, X3 28iX SUV, Z4 23i Roadster, Z4 30i Roadster,

2012

125i Convertible, 125i Coupe, 128i Convertible, 128i Coupe, 323i Convertible, 323i Coupe, 323i Touring, 325i Convertible, 325i Coupe, 325i Sedan, 325xi Coupe, 328i Convertible, 328i Coupe, 328i Touring, 328xi Coupe, 328xi Touring, 330i Convertible, 330i Coupe, 330i Touring, 520Li Sedan, 523Li Sedan, 530Li Sedan, 530i Sedan, 530i Touring, 730Li Sedan, 730i Sedan, X3 28iX SUV,

2013

125i Convertible, 125i Coupe, 128i Convertible, 128i Coupe, 325i Convertible, 325i Coupe, 325xi Coupe, 328i Convertible, 328i Coupe, 328xi Coupe, 330i Convertible, 530Li Sedan, 530i Sedan, 530i Touring, 730Li Sedan, 730i Sedan,

2014

530Li Sedan, 730Li Sedan, 730i Sedan,

2015

730Li Sedan, 730i Sedan,

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. .

The N52 six-cylinder engine was found in many different BMW vehicles. The following instructions may differ slightly depending on year and model.

1. Remove the acoustic cover.

Click to enlarge image

- Remove the acoustical cover from the top of the engine.

For detailed instructions on removing the acoustic cover, please see our article Engine Acoustic Cover Removal – BMW N52 6 Cylinder Engine

View part diagram for this step

Locate and remove the Schrader valve cap from the fuel rail

Click to enlarge image

- Remove the cap from the Schrader valve, located on the side of the fuel rail as shown in the image.

- Depress the stem inside the Schrader valve (like letting the air out of a car tire) until their is no fuel pressure. Have a rag handy to catch any fuel that may drip out.

View part diagram for this step

Attach a fuel pressure gauge to the Shrader valve, start engine and record pressure

Click to enlarge image

- Attach a fuel pressure guage to the Schrader valve and start engine. Document the pressure level.

- The fuel pressure in the BMW N52 6-cylinder should be 72 psi.

- If your fuel pressure is low, you may have a faulty fuel pump or dirty fuel filter. If the fuel pressure is to high, there may be a kink in one of the fuel lines.

View part diagram for this step