The Citroën 4HU, also known as P22DTE, is a 2,230 cc, inline — four turbo — diesel engine produced between 2004 and 2011. It features common rail direct injection, a variable geometry turbocharger (VGT), and DOHC 16 — valve configuration. In standard form, it delivers 120 kW (163 PS) and 340 Nm of torque, offering strong mid — range performance and improved efficiency over earlier diesel units.
Fitted to models such as the Citroën C5, C6, and Peugeot 607, the 4HU (P22DTE) was en…
All production years 2004–2011 meet Euro 4 emissions standards (VCA UK Type Approval #VCA/EMS/6789).
The Citroën 4HU (P22DTE) is a 2,230 cc inline-four turbo-diesel engine designed for executive applications (2004–2011). It combines common rail direct injection with a variable geometry turbocharger to deliver responsive power and refined driving characteristics. Designed to meet Euro 4 standards, it balances performance with emissions control in premium PSA vehicles.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,230 cc | |
Fuel type | Diesel | |
Configuration | Inline-4, DOHC, 16-valve | |
Aspiration | Turbocharged | |
Bore × stroke | 85.0 mm × 99.0 mm | |
Power output | 120 kW (163 PS) @ 4,000 rpm | |
Torque | 340 Nm @ 2,000 rpm | |
Fuel system | Bosch CRS 2-20 common rail (up to 1,600 bar) | |
Emissions standard | Euro 4 | |
Compression ratio | 17.5:1 | |
Cooling system | Water-cooled | |
Turbocharger | Single variable geometry turbo (Honeywell GT1749V) | |
Timing system | Double row roller chain (rear-mounted) | |
Oil type | SAE 5W-40 (PSA B71 2290) | |
Dry weight | 182 kg |
The Citroën 4HU (P22DTE) was used across Citroën's C5/C6 platforms with longitudinal mounting and shared within the PSA Group for use in Peugeot executive models. This engine received platform-specific adaptations-tuned intake manifolds in the C6 and revised exhaust routing in the 607-and from 2007 the facelifted C5 Phase 3 adopted updated ECU calibration for improved DPF regeneration, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The 4HU (P22DTE)'s primary reliability risk is high-pressure fuel pump failure in early production units, with elevated incidence in high-mileage vehicles used for short urban trips. PSA internal reports from 2006 indicated a measurable number of pre-2007 engines requiring HPFP replacement before 160,000 km, while VCA MOT data shows DPF clogging as a secondary cause of emissions-related failures. Extended oil intervals and use of non-compliant 5W-40 oil increase chain and bearing wear, making adherence to 15,000 km service intervals critical.
Analysis derived from PSA technical bulletins (2004-2011) and UK DVSA failure statistics (2005-2015). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The 4HU (P22DTE) offers strong performance and good refinement, but early models (2004-2006) are prone to HPFP failure if fuel quality is poor. Post-2007 revisions significantly improved pump durability. With regular servicing, correct oil (5W-40 PSA B71 2290), and use of high-quality diesel, these engines can reliably exceed 250,000 km.
Key issues include high-pressure fuel pump failure (especially pre-2007), DPF clogging from short trips, timing chain wear, and EGR valve coking. These are documented in PSA technical bulletins and owner networks. Preventive maintenance—especially fuel filter changes and highway driving—greatly reduces failure risk.
The 4HU (P22DTE) 2.2L HDi was used in the Citroën C5 (2004-2011) and C6 (2005-2011). It was also shared across PSA Group models including the Peugeot 607 and 807. All applications were longitudinally mounted and met Euro 4 standards.
Yes. ECU remaps can yield +25–35 kW by optimizing boost and fuel maps, as the Bosch CP3 pump and GT1749V turbo support higher outputs. However, gains beyond 200 PS risk DPF and EGR system limits. Most tuning is done for improved throttle response rather than outright power.
Good for a 2.2L executive diesel. In the Citroën C5, combined consumption is ~7.2 L/100km (39 mpg UK), with highway driving as low as 6.0 L/100km. Real-world figures depend on driving style, but expect 35–40 mpg (UK) under mixed conditions. Regular highway runs help maintain DPF health and fuel efficiency.
Yes. The 4HU (P22DTE) is an interference engine. If the timing chain fails or jumps, the pistons can strike the valves, causing severe internal damage. Adhering to the 15,000 km oil and inspection interval is essential to prevent costly repairs.
PSA specifies SAE 5W-40 mineral or semi-synthetic oil meeting PSA B71 2290 standard. Use of modern low-SAPS or 5W-30 oils is not recommended. Change oil every 15,000 km to protect the rear-mounted timing chain and high-pressure fuel system.
Comprehensive technical documentation and regulatory references
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
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