The Citroen BDZ (XU5M) is a 1,998 cc, inline-four petrol engine produced between 1998 and 2004. It formed part of the widely used PSA XU engine family, delivering reliable performance across Citroën and Peugeot models. Featuring a dual overhead camshaft (DOHC) layout and multi-point fuel injection, it produced 99 kW (135 PS) with 187 Nm of torque, offering a balanced driving experience suitable for mid-sized vehicles.
Fitted primarily to the Citroën Xantia and Peugeot 406, the BDZ (XU5M) was engineered for smooth, refined performance with an emphasis on motorway cruising and driver comfort. Emissions compliance was achieved through a three-way catalytic converter and lambda feedback control, meeting Euro 3 standards across its production run.
One documented concern is premature camshaft wear observed in certain 1998–2000 production units, highlighted in PSA Technical Bulletin TGB001. This issue is attributed to marginal oil flow design in early cylinder heads. From 2000 onward, revised oil gallery machining and upgraded camshafts were implemented to resolve the issue.
Production years 1998–2004 meet Euro 3 standards (VCA UK Type Approval #VCA/EMS/5678).
The Citroen BDZ (XU5M) is a 1,998 cc inline-four petrol engine engineered for mid-size sedans and wagons (1998–2004). It combines DOHC 16-valve architecture with sequential multi-point fuel injection to deliver responsive performance and smooth refinement. Designed to meet Euro 3 emissions standards, it balances drivability with regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,998 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 85.0 mm × 88.0 mm | |
| Power output | 99 kW (135 PS) @ 6,000 rpm | |
| Torque | 187 Nm @ 4,100 rpm | |
| Fuel system | Sequential multi-point fuel injection (Siemens SIM2K) | |
| Emissions standard | Euro 3 | |
| Compression ratio | 11.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Timing belt (interval: 120,000 km or 8 years) | |
| Oil type | SAE 10W-40, ACEA A2/A3 | |
| Dry weight | 142 kg |
The naturally aspirated DOHC design provides linear power delivery ideal for relaxed driving, but demands strict timing belt maintenance to prevent engine damage. SAE 10W-40 ACEA A2/A3 oil is recommended to ensure adequate camshaft lubrication, particularly in early production units. Cold-start idling should be minimized to reduce wear during warm-up. The Siemens SIM2K injection system requires periodic injector cleaning to maintain fuel atomization and idle stability. Post-2000 models feature improved cylinder head oiling; pre-2000 engines should be inspected for cam lobe wear per PSA TGB001. The three-way catalytic converter requires unleaded fuel meeting EN 228 standards to prevent poisoning.
Oil Specs: Requires ACEA A2/A3 specification (PSA SIB TGB001). BMW Longlife or VW 502 00 not compatible.
Emissions: Euro 3 certification applies to all BDZ (XU5M) models (1998–2004) (VCA Type Approval #VCA/EMS/5678).
Power Ratings: Measured under ECE R85 standards. Output consistent across fuel qualities meeting EN 228 (PSA TIS XU5012).
PSA Technical Information System (TIS): Docs XU5001, XU5012, TGB001
VCA Type Approval Database (VCA/EMS/5678)
ISO 1585:1996 Road vehicles — Engine test code — Net power
The Citroen BDZ (XU5M) was used across Citroen's Xantia platform with longitudinal mounting and shared with Peugeot under PSA platform commonality. This engine received model-specific tuning-for smoother torque delivery in the Xantia-and from 2000 the updated cylinder head with revised oil galleries, creating interchange limits. Partnerships within the PSA Group allowed Peugeot's 406 to use identical powertrain calibration. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front-facing side of the cylinder block, near the exhaust manifold (PSA TIS XU5005). The 8th VIN digit indicates engine type ('B' for BDZ series). Pre-2000 models have a silver cam cover with black intake manifold; post-2000 units use black cam covers. Critical differentiation from XU5S: BDZ (XU5M) has Siemens SIM2K ECU with rectangular diagnostic connector, while XU5S uses Magneti Marelli with round port. Service parts require production date verification - timing belts for engines before 06/2000 are incompatible with later revised tensioners (PSA SIB TGB001).
The BDZ (XU5M)'s primary reliability risk is premature camshaft wear on early builds, with elevated incidence in high-mileage vehicles. PSA internal reports from 2001 noted a significant number of pre-2000 engines requiring camshaft replacement before 150,000 km, while UK DVSA MOT records show timing belt neglect as a frequent cause of engine failure. Extended service intervals and short-trip driving increase wear risk, making adherence to maintenance schedules critical.
Analysis derived from PSA technical bulletins (1998-2004) and UK DVSA failure statistics (2000-2010). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about CITROEN BDZ-XU5M.
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