Description

This is a workshop DPF cleaning service for the genuine Vauxhall Diesel Particulate Filter (OEM part number 55204931) fitted to the Vauxhall Astra 1.9 CDTI (Z19DTH engine) from 2004-2010. Our professional ultrasonic and thermal cleaning process restores blocked filters to over 98% of their original efficiency for a fraction of the cost of a new unit.

A Diesel Particulate Filter, or DPF, is a critical emissions control device fitted to modern diesel vehicles. Its primary function is to trap harmful particulate matter (soot) from the exhaust gas. Over time, the DPF uses a process called regeneration, where it burns this soot off at high temperatures, turning it into a much smaller amount of fine ash. However, if regeneration cycles are frequently interrupted or fail, the filter becomes blocked with a mixture of soot and hardened ash, leading to engine performance issues and warning lights.

Common failure modes for the DPF on the Z19DTH engine are almost always related to blockage. This is often caused by a driving pattern dominated by short, low-speed journeys where the exhaust system never gets hot enough to initiate a full regeneration. Other root causes can include faulty pressure or temperature sensors providing incorrect data to the ECU, a malfunctioning EGR valve, leaking fuel injectors, or oil passing from a worn turbocharger, all of which can create excessive soot and overwhelm the filter.

At Gap Turbos, our DPF cleaning service is a comprehensive solution. We first conduct a flow test to measure the level of blockage. The unit is then submerged in a specialist ultrasonic cleaning tank to break down the hardened carbon and ash deposits, followed by a controlled thermal regeneration cycle in our DPF oven to bake out any remaining particulates. A final flow test confirms the filter has been successfully restored. This workshop-based service is significantly more effective than mobile chemical cleaning or forced regenerations alone and is typically 70-90% cheaper than buying a new replacement unit from a main dealer. Please note that DPF removal is illegal in the UK and will result in an MOT failure.

What this diesel particulate filter (DPF) fits

This cleaning service is for the original equipment DPF, part number 55204931 (alternative part number BM11035), fitted to the following vehicle:

• Vehicle: Vauxhall Astra H
• Engine: 1.9 CDTI
• Engine Code: Z19DTH
• Years: 2004, 2005, 2006, 2007, 2008, 2009, 2010
• Euro Class: Euro 4

Contact Gap Turbos today for a firm quote on our DPF cleaning service. All our cleaning work is backed by a 12-month, unlimited mileage warranty against defects.

Specifications

Vehicle fitment

• Vauxhall Astra 1.9 CDTI

Common faults & troubleshooting

• DPF warning light illuminated: The ECU has detected that soot loading has exceeded its predefined limit, indicating a regeneration is required or has failed.
• Vehicle in ‘limp mode’ (reduced power): The engine’s power is restricted by the ECU to prevent damage from excessive exhaust back-pressure caused by the blockage.
• Noticeably worse fuel consumption: The engine must work harder to push exhaust gases through the blocked filter, leading to increased diesel usage.
• Engine struggles to start or stalls: In severe cases, the back-pressure can be so high that it chokes the engine, making it difficult to start or keep running at idle.
• Failed MOT emissions test: A blocked, cracked, or tampered-with DPF will result in an immediate failure on the smoke and particulate matter test.
• Strong smell of unburnt diesel: This can occur when the ECU is attempting and failing to perform an active regeneration, injecting extra fuel that doesn’t get burnt.

Fitting notes for this unit

• Always use new gaskets: The metal gaskets between the DPF and the turbocharger/exhaust system are crush-type and are strictly single-use. Re-using them will cause leaks.
• Inspect sensor ports: Before refitting the pressure and temperature sensors, ensure their ports and threads on the DPF body are clean and undamaged to prevent false readings.
• Reset ECU adaptations: After fitting the cleaned DPF, it is essential to use a diagnostic tool to reset the DPF soot and ash counters. The ECU must be told it has a ‘new’ filter.
• Address the root cause: Before starting the car, ensure the original cause of the DPF blockage (e.g., faulty EGR valve, incorrect oil, sensor fault) has been diagnosed and repaired to prevent a repeat failure.
• Check differential pressure pipes: Inspect the small rubber hoses going to the pressure sensor for any splits, blockages, or perishing, as a fault here will mimic a blocked DPF.
• Initiate a dynamic regeneration: After fitting and resetting the ECU, perform an extended road test that allows the vehicle to run a full, dynamic regeneration cycle to confirm the entire system is functioning correctly.

Alternative part numbers

This turbo is also referenced by:

• BM11035 — Vauxhall DPF OE BM11035 (Vauxhall Astra 1.9 CDTI, Z19DTH, Euro 4)

Frequently asked questions