my BMW 3 Series E90/E91 has a strong chemical smell from the vents, what should I do?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to avoid any electrical issues.

2. Replace Cabin Air Filter

1. Locate the cabin air filter housing, usually found behind the glove compartment.
2. Remove the glove compartment by unscrewing any screws and detaching clips.
3. Open the cabin air filter housing cover and carefully remove the old filter.
4. Install the new cabin air filter, ensuring it is oriented correctly (check for airflow arrows).
5. Reassemble the glove compartment and secure it with screws.

3. Inspect and Repair HVAC System

1. Remove any necessary panels to access the HVAC unit.
2. Check for mold or mildew; if present, clean the ducts with a specialized cleaner or a mixture of vinegar and water.
3. Inspect the heater core for leaks and replace if damaged.
4. If coolant leaks are detected, replace damaged hoses or components and refill with manufacturer-recommended coolant.

4. Flush and Clean

1. If the odor persists, consider flushing the HVAC system with a cleaning solution specifically designed for air conditioning systems.
2. Follow manufacturer's instructions for the cleaning solution.
3. Allow the system to dry completely before reassembling any components.