The Citroën HMZ, known internally as the EB2, is a 1,397 cc, inline — four petrol engine produced between 2004 and 2010. It belongs to the PSA EB engine family, featuring a DOHC 16 — valve configuration with multi — point fuel injection. Designed for compact city cars and small hatchbacks, it delivers 74 kW (101 PS) and 130 Nm of torque, providing responsive urban performance with strong low — end driveability.
Fitted to models such as the C3 and C2, the HMZ engine was engineered f…
All HMZ (EB2) production (2004–2010) complies with Euro 4 emissions standards (VCA UK Type Approval #VCA/EMS/6123).
The Citroën HMZ (EB2) is a 1,397 cc inline-four petrol engine engineered for compact and city vehicles (2004–2010). It combines DOHC 16-valve architecture with sequential multi-point injection to deliver agile low-end response. Designed to meet Euro 4 standards, it balances urban drivability with regulated emissions control.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,397 cc | |
Fuel type | Petrol (Unleaded, 95 RON) | |
Configuration | Inline-4, DOHC, 16-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 78.5 mm × 72.0 mm | |
Power output | 74 kW (101 PS) @ 6,000 rpm | |
Torque | 130 Nm @ 4,000 rpm | |
Fuel system | Sequential multi-point fuel injection (Siemens SIMOS 7.4) | |
Emissions standard | Euro 4 | |
Compression ratio | 10.8:1 | |
Cooling system | Water-cooled, thermostatically controlled | |
Turbocharger | Not applicable | |
Timing system | Timing belt (replacement interval: 120,000 km or 8 years) | |
Oil type | SAE 5W-30, ACEA A1/B1 | |
Dry weight | 108 kg |
The Citroën HMZ (EB2) was used across Citroën's B-segment platforms with transverse mounting and shared within the PSA Group for applications in Peugeot variants. This engine received platform-specific adaptations-shorter intake manifolds in the C2 and revised engine mounts in the C3-and from 2007 the Euro 4-compliant EB2D update introduced revised valve timing, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The HMZ (EB2)'s primary reliability risk is timing belt tensioner degradation, with elevated incidence in high-mileage or stop-start environments. Internal PSA quality reports from 2006 noted a significant number of pre-2007 units requiring premature belt replacement, while UK DVSA records show timing-related failures contributing to MOT failures in high-mileage examples. Extended service intervals and thermal stress increase risk, making adherence to 8-year/120,000 km replacement critical.
Analysis derived from PSA technical bulletins (2004-2010) and UK DVSA failure statistics (2006-2012). Repair procedures should follow manufacturer guidelines.
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The HMZ (EB2) is generally robust when maintained, but pre-2007 models are prone to timing belt tensioner failure. Later revisions improved durability with updated materials. Regular timing belt service at 120,000 km or 8 years is essential. Using correct oil (5W-30 ACEA A1/B1) and addressing coolant leaks promptly ensures long-term reliability.
Key issues include timing belt tensioner wear (especially pre-2007), coolant leaks from the thermostat housing, lambda sensor degradation, and intake manifold flap failure. These are documented in PSA service bulletins. Proactive replacement of high-risk components significantly improves longevity and prevents costly engine damage.
The HMZ (EB2) was used in the Citroën C3 (2004–2010) and C2 (2004–2009). It was also shared with Peugeot models like the 107 and 206. All units comply with Euro 4 emissions standards (VCA Type Approval #VCA/EMS/6123).
Limited tuning potential exists. ECU remaps can yield +5–8 kW by optimizing fuel and ignition maps, but gains are modest due to natural aspiration. Supporting mods like performance intake and exhaust offer marginal improvements. Significant power increases require forced induction, which is complex and not OEM-supported.
In combined driving, expect 6.8–7.5 L/100km (41–39 mpg UK). Highway economy improves to ~5.8 L/100km (~48 mpg UK), while city driving may reach 8.5 L/100km (~33 mpg UK). Real-world figures depend on driving style and vehicle weight, with the C2 being slightly more efficient than the C3.
Yes. The HMZ (EB2) is an interference engine. If the timing belt fails, pistons contact open valves, causing severe internal damage. This makes strict adherence to the 120,000 km or 8-year replacement interval absolutely critical. Any signs of belt wear or tensioner noise require immediate inspection.
PSA specifies SAE 5W-30 oil meeting ACEA A1/B1 standards (PSA B71 2291). Use high-quality synthetic oil and change every 12,000 km or annually. Proper oil ensures valve train protection and reduces sludge buildup, especially important for long-term timing belt and bearing health.
Comprehensive technical documentation and regulatory references
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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