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Repair Summary
This article gives detailed instructions on replacing the DISA valves 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 vehicle with the N52 engine including most 2004-2013 1, 3, 5, 6, 7, X1, X3, X5, and Z4 series 6 cylinder models with minor modifications to the repair steps.
Replacing the DISA valves in the BMW N52 6 cylinder engine may cure sluggish acceleration issues.
In 2004 BMW introduced a new generation of high efficient six-cylinder engines to replace the aging workhorses from the 1990's. The N52 was a direct replacement for the M54 engine - it featured an improved air management system that created higher torque over a broader range of engine speed. An integral part of achieving this broader torque range in the N52 engine was a new 3-stage intake manifold with dual differential intake air control (DISA) valves.
The DISA valves, located on the inner and outer sides of the manifold, are simply electronically controlled flaps that redirect airflow inside of the intake manifold at different engine speeds. Engines that do not use DISA valves can only produce torque over a very narrow engine speed band. Redirecting airflow inside the 3 stage intake manifold with dual DISA valves helps the N52 six-cylinder engine deliver torque throughout the low, mid, and high engine speed ranges creating a more powerful and efficient motor. Like all mechanical parts in the engine compartment, the DISA valves are prone to failure after years of operation and will eventually need to be replaced.
The classic symptom of DISA valve failure is a lack of power when the accelerator pedal is depressed. The DISA valve flaps are also prone to breaking off and getting lodged inside the intake manifold - this often causes a mysterious "humming" sound that can even be felt in the accelerator pedal. In extreme cases, the broken flap can shatter getting lodged inside the valves and cylinders causing extensive engine damage.
Replacing the exterior DISA valve is simple since it is easily accessed from the outside of the engine. Unfortunately due to its confined location, the interior DISA valve can only be replaced with the intake manifold removed. There is no other way to get it out. Always replace both the interior and exterior DISA valves when doing this repair. Only replacing one valve without the other is like changing your dirty engine oil but not replacing the filter...you are only doing half the job. We give full detailed instructions below on removing the DISA valves from most vehicle with the N52 6 cylinder engine. For instructions on removing the intake manifold from the N52 engine, please refer to our repair article BMW N52 Intake Manifold Removal – 1,3,5,6,7,X1,X3,X5,Z4 6 Cyl. prior to starting this repair.
View the detailed parts diagram for this repair.
Includes detailed part diagrams, part numbers and links to purchase all of the required components needed to complete this repair.
Before starting this repair, you must have the following required parts.
N52 Engine
This is the same factory DISA valve that would be installed at the BMW dealership.
N52 Engine
Air adjustment unit controls the path of the air in the intake manifold, allowing either a shorter or longer runner length. A common source of trouble causing low RPM sluggishness and accompanied by a clicking sound from the engine bay.
Section 1 - Intake manifold removal
As previously discussed, the intake manifold must be removed from the N52 engine in order to replace the interior DISA valve. There is simply not enough clearance to remove the valve otherwise. Now is an excellent time to replace your oil separator and crankcase breather hoses while you have the intake removed.
- For complete steps on removing the intake manifold from your N52 engine, please see our repair article BMW N52 Intake Manifold Removal – 1,3,5,6,7,X1,X3,X5,Z4 6 Cyl. .
Section 2 - Replacing the BMW N52 DISA valves
After removing the intake manifold, extracting and replacing the DISA valves is relatively simple. Now is a great time to clean out the inside of the intake manifold while you have the DISA valves and throttle body removed - oil and debris build up inside the manifold affecting performance.
- Lay the intake manifold on a clean bench so all of its components can be easily accessed.
- Starting with the exterior DISA valve, use a T25 torx bit to first remove the metal wiring harness bracket that blocks access to the valve.
- Use the T25 torx bit to remove the exterior DISA valve's four mounting screws.
- Using a plastic trim removal tool, carefully pry the valve out of the intake manifold. DO NOT use a metal tool to pry it out...you could damage the plastic intake manifold causing vacuum leaks.
- The flap on our exterior DISA valve broke off. Make sure to remove any broken parts from inside the manifold to avoid them getting caught in the cylinder head. Now is also a great time to thoroughly clean the inside of the intake manifold.
- Install a fresh DISA valve. Press firmly with the palm of your hand until the valve is firmly set inside the manifold. Replace the mounting screws and tighten until snug.
- In order to access the interior DISA valve mounting screws, the throttle body must be removed. It is held in place with four 10mm bolts.
- Using a T25 torx bit, remove the interior DISA valve mounting screws.
- Use a plastic trim removal tool to carefully pry the DISA valve out of the manifold. Install a new valve and tighten the mounting screws until snug.
- Replace the throttle body gasket. Reinstall the throttle body and torque the mounting bolts to 10.5 NM (8 ft-lb).
- Reinstall the intake manifold per our article BMW N52 Intake Manifold Removal – 1,3,5,6,7,X1,X3,X5,Z4 6 Cyl. .
