Volkswagen Caravelle Diesel Particulate Filter DPF T4 (1990-2004)

The Diesel Particulate Filter (DPF) is a device installed in the exhaust system of diesel vehicles like the Volkswagen Caravelle T4 to trap soot and fine particles produced by incomplete diesel combustion. It uses a ceramic honeycomb substrate to capture particulates and significantly reduces harmful emissions from the engine exhaust.

Most Volkswagen Caravelle T4 models produced between 1990 and 2003 were not originally equipped with a DPF, as this component became standard mainly from 2005 onwards with Euro 4 norms on newer models like the T5. However, aftermarket DPF kits compliant with Euro 4 standards are available for diesel T4 models.

The DPF traps soot particles in a ceramic filter, allowing exhaust gases to flow through while retaining particles larger than the filter pores, which creates backpressure.

• Passive regeneration: Occurs at high exhaust temperatures (350-500°C) during long highway drives over 60 km/h at 2500-3000 RPM. Soot burns off naturally through catalytic conversion into CO2.
• Active regeneration: The engine control unit injects extra fuel to raise exhaust temperature and burn off trapped soot when passive regeneration is insufficient.

A warning light usually comes on when the DPF is about 45% full, signaling that regeneration is needed.

Volkswagen recommends manual regeneration procedures for DPF maintenance on diesel vehicles, including the Caravelle T4 (modernized or similar models):

• Ensure the fuel tank is at least 1/4 full, ideally over 1/2 full.
• Drive at speeds above 60 km/h at 2500-3000 RPM (using Tiptronic gear) for 25-30 minutes on a highway or fast road.
• Continue driving for 10 minutes after the DPF warning light turns off.

Regular long-distance drives at high engine RPM help passive regeneration, while short urban trips should be avoided to prevent clogging.

Use a diagnostic tool to read the DPF differential pressure sensor (measuring pressure before and after the DPF). Typical pressure ranges include:

• Engine off: 0-5 mbar (higher suggests wiring or sensor faults)
• Warm idle: 0-10 mbar (above 10 mbar requires further diagnostics)
• 2500-3000 RPM (engine <2L): 20-60 mbar normal
• 2500-3000 RPM (engine >2L): 70-90 mbar normal; 160-300 mbar indicates soot buildup
• Over 300 mbar: requires professional cleaning or replacement

Symptoms of DPF issues include illuminated DPF light, engine power loss, and high backpressure.

DPFs can be cleaned manually by removal and professional cleaning (including ultrasonic methods) or replaced with new aftermarket units. Cleaning costs range from about €300 to €500, while replacement is more expensive.

Example aftermarket DPF for Caravelle Transporter 4Motion 2.5 TDI (2006-2009, Euro 4) measures approx. 430 mm length and weighs 5 kg, sold with a mounting kit.

• Always check vehicle specific compatibility and sensor requirements before replacement.
• After replacement, ensure proper installation by a specialist to avoid ECU faults or engine limp mode.

Preventive maintenance and timely regeneration can extend DPF life and avoid costly repairs.

Signs of a clogged DPF include:

• DPF warning light illuminated on the dashboard
• Loss of engine power or poor performance
• Increased fuel consumption
• Unusual sounds from the exhaust system indicating pressure buildup

If these signs appear, have the DPF pressure sensor readings checked quickly to assess soot saturation and plan cleaning or regeneration.

Krosfou offers high-quality, brand-new stainless steel DPFs manufactured in Europe with a 3-year warranty and compliance with manufacturer specifications and European regulations. These parts feature advanced ceramic honeycomb monoliths with unique thin-layer coatings for durability and performance.

• Products shipped quickly with options for express delivery.
• Technical support available for installation and compatibility checks via VIN or reference numbers.
• 30-day free return policy for unused products in original packaging.

Choosing durable, certified DPFs helps maintain engine performance, reduce emissions, and protect the environment.