Citroen C8 Diesel Particulate Filter DPF (2002-2014)

The Diesel Particulate Filter (DPF) on Citroën C8 Diesel, especially for 2.0 HDi engines (RHK/DW10UTED4 120 hp or RHT/DW10ATED4 110 hp), is an additive-type filter developed by PSA. It traps fine particulate matter (down to 0.1 micron) from exhaust gases using a porous silicon carbide structure and includes an additive tank to lower combustion temperatures of particulates.

The system integrates a dedicated additive reservoir, engine control unit managing HDi injection, differential pressure sensors, temperature probes, and an intake air heater. It is located within the exhaust line after the turbocharger and combined with the catalytic converter.

Exhaust gases pass through alternating channels in the DPF forcing particulates to accumulate on the walls, forming a soot layer filtered from the gases. A special additive is injected from its reservoir to reduce soot combustion temperature, enabling effective burning of trapped particles during regeneration phases.

Sensors continuously monitor pressure difference upstream and downstream of the filter, gas temperature, and additive levels to manage filter efficiency and trigger regeneration when needed.

DPF regeneration is the process of burning off accumulated soot to restore filter permeability. It is triggered automatically by the engine control unit every 350 to 800 km, raising temperatures to 500-600°C using post-injection, air heating, and controlled engine speed.

• Passive regeneration occurs naturally during long, high-speed driving.
• Assisted regeneration happens in moderate load conditions to anticipate soot burning.
• Forced regeneration is done in workshops using special diagnostic tools for engine idling and high RPM post-injection cycles.

The ECU monitors stages of filter load and triggers appropriate actions from normal operation to immediate regeneration or degraded mode in case of excessive clogging.

Common problems include progressive clogging from soot and additive buildup, mostly caused by frequent short trips or stop-and-go driving.

• Warning lights on the dashboard
• Loss of engine power
• Increased fuel consumption due to frequent regenerations
• Degraded mode activation limiting engine speed and altering injection

Catching these symptoms early and performing appropriate maintenance is critical to avoid costly repairs.

Maintenance includes regularly checking and refilling the additive reservoir and driving at higher engine speeds periodically to enable natural regeneration.

• Cleaning the DPF to remove soot and additive residues when clogged
• Replacing the DPF if cleaning is insufficient, with original quality parts
• Using diagnostic tools to perform forced regeneration and reset faults

Illegal modifications such as mechanical or electronic removal of the DPF are strongly discouraged due to environmental regulations and risk of degraded engine operation.

The Citroën C8 Diesel DPF is made from a high-quality ceramic material — specifically a porous silicon carbide monolith. This design is preferred for its excellent filtration efficiency at the required particle size and durability under high thermal stress.

Metallic filters are not typically used in this application due to different performance and cost characteristics. The ceramic substrate coated with rare metals provides the required catalytic and filtering properties necessary for emissions control.

Replacement diesel particulate filters for Citroën C8 Diesel 2.0 HDi models are available as original quality new parts, manufactured with durable stainless steel and high-grade monolith cores.

• Ensure compatibility with your vehicle model and engine code (RHK, RHT, DW10UTED4, DW10ATED4)
• Confirm that products comply with European emission and quality standards (E24-103R certification)
• Use genuine additive refill kits for the associated reservoir to maintain filter efficiency
• Professional installation is recommended to guarantee correct sensor fitment and performance

Check professional online catalogs or trusted aftermarket suppliers who provide warranty and technical support.

To maintain optimal function and extend the life of the DPF in your Citroën C8 Diesel:

• Regularly check additive levels and refill as required
• Avoid excessive short journeys where the engine does not reach operating temperature
• Periodically drive at sustained higher speeds to allow passive regeneration
• Address warning lights promptly and have diagnostics performed at authorized garages
• Follow the manufacturer’s maintenance schedule strictly, including injector and sensor replacements

Proper care avoids clogging and forced replacements, ensuring your car meets emission standards and runs efficiently.