Home Repair and Service Manual VANOS Valve Actuator Replacement – BMW B46/B48 Turbo 4 Cyl. Engine

VANOS Valve Actuator Replacement – BMW B46/B48 Turbo 4 Cyl. Engine

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VANOS Valve Actuator Replacement – BMW B46/B48 Turbo 4 Cyl. Engine

BMW VANOS stands for Variable Valve Timing System. In layman's terms, it is basically a system that changes the camshaft timing in relation to engine speed by using variable oil pressure. At lower speeds, the VANOS opens the engine valves later creating a smoother and more efficient engine. As engine speed increases, the VANOS opens the valves earlier creating greater torque and better fuel economy. The VANOS valve actuators are simply solenoids that supply the oil pressure necessary to achieve this. When the solenoids fail, there is no more oil pressure and the camshafts stick in a fixed position causing a rough running engine and a dreaded service engine light on your dashboard. The good news is the actuators are relatively inexpensive and easy to install. This article gives detailed instructions on installing VANOS valve actuators in BMW B46/B48 four-cylinder engines.
Not sure which engine you have in your BMW? Use our engine finder tool to easily identify it!
Possible Symptoms: Rough running engine, poor fuel economy, poor performance at all speeds
This repair can be used on the following BMW models:
Advanced level repair.

Step 1 - Purchase Parts

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

VANOS Valve Actuator

Like all mechanical engine parts in your BMW, the VANOS valve actuators have a definitive life span and will eventually fail leaving you with a rough running engine and a big frown on your face. The good news is they are relatively inexpensive. These Genuine BMW actuators are the same factory ones that would be installed at the BMW dealership.

Wiper Arm Puller Tool

Those pesky windshield wiper arms...they seem to always be in the way of some important engine repair on your BMW. This inexpensive tool quickly pulls the wiper arm safely of its motor without breaking it. NEVER try and pry a wiper arm off with a screwdriver prybar...you could seriously damage both the arm and the motor.

Pin Wrench

If you are removing and installing VANOS valve actuators in BMW engines, you must have this tool. The BMW pin wrench easily turns the actuator making removal and installation a snap.

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. .
1. Preparing for VANOS valve actuator removal
Remove the acoustic cover from the engine
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- Remove the acoustic engine cover by pulling it up until it releases from its rubber grommets.

View part diagram for this step
VANOS Valve Actuator Replacement – BMW B46/B48 Turbo 4 Cyl. Engine
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- Remove the right cover (2) from the engine compartment by removing the fasteners (1) and unlocking the latch mechanism (3).

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VANOS Valve Actuator Replacement – BMW B46/B48 Turbo 4 Cyl. Engine
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- Remove the left cover (3) from the engine compartment by removing the fasteners (1) and unlocking the latch mechanism (2).

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remove the protective caps from the wiper arms
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- Remove the protective cap from the left and right wiper arms and remove the nut below it.

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use a wiper arm puller tool to remove the right and left wiper arms
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- Using a wiper arm puller tool, remove the wiper arms from the vehicle.

- If you need a wiper arm removal tool, please see our parts section above.

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remove the cowl panel from under the windshield
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- Remove the rivets (1) from top of cowl panel. Loosen the snap fastners (2) by turning counterclockwise 90 degrees. Grasp the cowl cover (3) and remove from vehicle.

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remove the strut brace
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Remove the strut brace by first unsnapping the top bolt cover (1). Remove the two anchor bolts.

Next, remove the two bolts anchoring the strut to the body of the vehicle (2).

Remove the strut brace from the engine compartment.

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detach the positive battery cable and remove the engine sealing gasket
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- Detach the positive battery cable from the sealing gasket (2).

- Remove the anchor rivet (1).

- Remove the sealing gasket in the direction shown in image (2).

VANOS Valve Actuator Replacement – BMW B46/B48 Turbo 4 Cyl. Engine
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- Remove the upper firewall cover (2) by removing its screws (1).

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remove the bolts anchoring the right engine partition
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- Remove the two torx bolts anchoring the right engine partition to the firewall.

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remove the body nuts anchoring the engine partition
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- Remove the three nuts anchoring the left and right engine partitions to the firewall.

- Grasp the right engine partition and remove it from the engine compartment.

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2. Replacing the VANOS valve actuators
Technical Information

The VANOS valve actuators are located on the rear of the engine. The BMW Repair Guide strongly recommends using a BMW pin wrench (part #83302360895) to remove and install the actuators. If you need this tool, please see our parts block above.

psotion pin wrench on the intake actuator
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- Locate the two VANOS valve actuators on the rear of the engine.

- Starting with the intake actuator (1), postion the pin wrench tool on the front of the actuator as shown in the image.

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turn intake actuator 45 degrees counter clockwise
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- Turn the intake actuator approximately 45 degrees counter-clockwise until it releases from the cylinder head cover.

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position wrench on exhaust actuator
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- Next, position the pin wrench on the exhaust actuator (1).

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turn exhaust actuator approximately 45 degrees counter clockwise
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- Turn the exhaust actuator approximately 45 degrees counter-clockwise until it release from the cylinder head.

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unplug both actuators
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- Unplug both actuators (1) and remove from the cylinder head cover.

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3. Installation

Follow the above steps in reverse to install the actuators and reassemble the vehicle.

- Strut brace mounting bolts torque to 56Nm (41 ft-lb).

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