Description
Filter Box 1.6 HDi 80 kW 9HZ For CITROËN C5 II, X7 And PEUGEOT 407
This filter box is designed for the 1.6 HDi (9HZ) 80 kW diesel engines used in Citroën C5 II (X7) and Peugeot 407 models. It replaces the original equipment housing identified by OE numbers such as 9685205580, 9651883080, 9648938580 and reference 1420N9. The unit secures the air filter element, protects the MAF sensor and intake tract from dirt and moisture, and helps maintain correct air flow for reliable combustion—an essential component for workshop repairs and DIY maintenance. Mechanics and car enthusiasts often search by part number (9685205580, 9651883080, 9648938580, 1420N9) when sourcing this item.
Technical Information
- Manufacturer: Stellantis / Citroën / Peugeot
- Model: Citroën C5 II (X7); Peugeot 407
- Product Codes: 9685205580, 9651883080, 9648938580, 1420N9
- Additional Numbers: Engine Code 9HZ; Power 80 kW; Engine Size 1.6 HDi
Function And Advantages
The filter box houses the air filter element and ensures a sealed, clean airflow into the engine. It protects the Mass Air Flow (MAF) sensor and downstream components from dust, water and debris, reduces intake noise and supports consistent engine performance and fuel efficiency. Correct sealing of the housing is important to avoid unmetered air that can cause rough idle or fault codes.
Installation Recommendations
- Prepare Tools: Basic hand tools, screwdrivers and pliers. Wear gloves and eye protection.
- Remove Intake Duct: Loosen clamps on the intake duct and remove any retaining clips or screws.
- Disconnect Sensors: Carefully unplug the MAF sensor connector (if fitted) and remove the sensor from the housing if required. Handle sensor and wiring with care to avoid damage.
- Unclip Housing: Release mounting clips and remove the old filter box. Inspect mounting points and rubber seals for wear.
- Transfer Components: Transfer any brackets, fittings or the MAF sensor to the new housing, ensuring correct orientation and secure fixing.
- Fit And Seal: Install the new filter box with a new or inspected air filter element, tighten clamps securely and ensure all seals and ducts are correctly seated to prevent air leaks.
- Final Check: Start the engine and check for intake leaks or fault codes. Verify that all clips and hoses are secure.
Recommended Service Interval
Inspect the filter box at regular service intervals and whenever the air filter is replaced. Depending on driving conditions, inspect every 20,000–40,000 km or during scheduled maintenance. Replace the housing immediately if cracked, damaged or if mounting points are broken.
Most Common Failure Reasons
The housing typically fails due to plastic fatigue and broken mounting tabs caused by age and heat cycling in the engine bay, impact damage from road debris or improper handling, and seal deterioration that allows unfiltered air or moisture into the intake. Oil contamination from turbochargers or valve-train systems can accelerate degradation. Damage often presents as visible cracks, loose clips, rattles, or intake air leaks that trigger engine management warnings.
Choose the correct OE-numbered filter box (9685205580 / 9651883080 / 9648938580 / 1420N9) to ensure proper fitment and restore reliable air filtration and engine performance for your Citroën C5 II (X7) or Peugeot 407 with the 1.6 HDi 9HZ engine.
