This article gives detailed instructions on replacing the mass air flow sensor (MAF) in a BMW vehicle with the N52 6 cylinder engine. Even though we used a 2006 530xi to perform this repair, this article can be applied to any BMW vehicle with the N52 engine including most 2004-2013 1, 3, 5, 6, 7, X1, X3, X5, and Z4 models minor modifications to the repair steps.
A BMW mass air flow sensor (MAF) repair on your N52 6 cylinder engine can help cure rough idles and clear instrument cluster errror lights.
One of the most misunderstood components of the BMW engine intake system is the mass air flow sensor, often referred to as the MAF (or the “hot-film air mass meter” for those hardcore mechanics). The mass air flow sensor is part of the engine’s air management system that includes all of the components involved with delivering metered fresh air to the cylinders. It is located on the intake pipe directly downstream from the intake muffler (air filter box).
The MAF is in charge of calculating how much air is entering the engine through the air filter element. This data is sent to the engine control module (the ECU…or sometimes referred to as the DME on BMWs) where it is used to adjust the amount of fuel being sprayed into the cylinders by the injectors. This delicate balance of measuring airflow and adjusting fuel delivery is what makes the BMW N52 six-cylinder engine so economically efficient and run so smoothly.
Obvious signs that your BMW N52’s mass air flow sensor is failing are a rough idling engine (especially when warm) and poor acceleration. It will also (usually) cause a Service Engine Light (SEL) to appear in the instrument cluster. For those home mechanics with a diagnostic scanner, a bad mass air flow sensor will normally throw one of the following error codes: 2D15 or 2D16.
Since the rough idling and poor performance issues can also be attributed to other problems with your BMWs engine, it is best to diagnose your N52 six-cylinder before replacing the mass air flow sensor.
Replacing the mass air flow sensor in your BMW N52 engine is an extremely simple process that takes about ten minutes to perform in most affected vehicles. We strongly recommend attempting to clean your MAF prior to purchasing a new one with CRC Electronic Cleaner…some times dirt can accumulate on the internal element causing it to malfunction. That being said if your BMW’s N52 engine has 120,000 plus miles on it, then it makes better sense just to replace the entire sensor with a new one.
1. Mass Air Flow Sensor (MAF) (required) – The mass air flow sensor in your BMW N52 six cylinder engine is a sensitive device that is manufactured under strict tolerances. The BMW Repair Guide only recommends purchasing a high-quality MAF from a reputable manufacturer. We give you several options based on your budget and brand preference.
As mentioned above, the mass air flow sensor on the N52 engine is conveniently located on the air intake pipe next to the intake muffler (air filter housing). Care should always be taken when disassembling your intake system…cracking a pipe or fitting can cause vacuum leaks.
- Locate and identify the mass air flow sensor. It is located on the intake pipe just downstream of the intake muffler.
- Remove the lid from the intake muffler. In most models, the lid is held in place with plastic latches.
- Using a metal pick, GENTLY lift the plastic retaining tab on the mass air flow sensor plug. Unplug the mass air flow sensor.
- Use a flat blade screwdriver to loosen the hose clamp securing the intake pipe to the intake muffler lid.
- Remove the intake muffler lid from the vehicle. Using a T25 torx bit, remove the two screws securing the mass air flow sensor to the intake muffler lid. Pull the sensor free from the lid.
- Remove the mass air flow sensor from the intake muffler lid.
- Replace the sensor and reassemble the vehicle following the above steps in reverse.