Bosch C3723WS Cabin Air Filter

Bosch Cabin Filter for BMW HVAC Systems

Bosch C3723WS is an activated carbon cabin air filter built for BMW applications that need OE-standard HVAC filtration and odor control. It uses a 5-layer design with an added carbon layer to capture exhaust-related gases and reduce unwanted cabin odors in BMW 1 Series, 3 Series, and X1 models.

Key Features

• Activated charcoal filter media for cabin air filtration
• 5-layer construction with an additional carbon layer for odor reduction
• Helps absorb ozone, nitrogen oxide, sulfur dioxide, and hydrocarbons
• OEM standard part for direct-fit HVAC service
• Foam-based automotive material construction
• Recommended replacement interval: 12,000 miles
• Cross-reference: This part cross-references BMW 64319313519 for the same application.

Product Details

The Bosch Cabin Filter, Activated Carbon line is designed for drivers who want a cabin air filter that addresses both airborne particles and odor-causing gases. Bosch C3723WS uses activated charcoal media and a pre-filter layer to support cleaner airflow through the HVAC system while helping reduce outside smells entering the cabin. It is a direct service part for BMW models including the 2006-2013 BMW 323i, 325i, 325xi, 328i, 328i xDrive, 328xi, 330i, 330xi, 335i, 335i xDrive, 335d, 335is, 335xi, 135i, 135is, 128i, 1 Series M, and 2012-2015 BMW X1 applications listed in the fitment data. Search terms such as BMW cabin air filter activated carbon, Bosch C3723WS, and BMW HVAC filter replacement align with this part’s intended service use.

What It Helps Address

• Unwanted cabin odors from traffic, exhaust, and roadside air
• Reduced HVAC airflow caused by a loaded cabin filter
• Dust and airborne debris entering the passenger compartment
• Service intervals that call for routine cabin filter replacement
• BMW cabin air filtration needs for 1 Series, 3 Series, and X1 models

Installation Notes and Tips

Replace the cabin filter according to the vehicle service schedule or when airflow and odor control decline. Confirm the vehicle’s HVAC configuration before ordering, since fitment varies by model year and automatic temperature control on some BMW applications. Install the filter in the correct airflow direction if the housing marks a flow arrow, and inspect the filter housing for debris before closing the HVAC cover.

Quality Assurance

Bosch manufactures this cabin filter as an OEM standard replacement part for the listed BMW applications. The activated carbon design and multi-layer construction support consistent cabin filtration performance for routine HVAC maintenance.