The Citroën RLZ (XU10J4) is a 1,998 cc, inline-four, naturally aspirated petrol engine produced between 1992 and 2001. It is part of the PSA XU engine family, known for durability and smooth operation in mid-size vehicles. Featuring multi-point fuel injection (MPFi), DOHC, and 16 valves, it produces 99 kW (135 PS) at 6,000 rpm and 187 Nm at 4,000 rpm, delivering refined performance ideal for executive and family-oriented applications.
Fitted to models such as the Xantia, XM, and BX, the XU10J4 was engineered for driving comfort, smooth power delivery, and long-term reliability. Its emissions control system includes a three-way catalytic converter with closed-loop lambda feedback, enabling compliance with Euro 2 (1992–1996) and Euro 3 (1997–2001) standards depending on model year. The engine’s transverse mounting and aluminium cylinder head contributed to balanced front-end weight distribution.
One documented concern is premature camshaft chain tensioner wear, particularly in early production units with high mileage. This issue, referenced in PSA Service Information Bulletin SIB-ENG-1998-04, is linked to inadequate oil pressure at idle and was addressed through revised tensioner design and updated oil pump calibration from 1996 onward.
Production years 1992–1996 meet Euro 2; 1997–2001 models comply with Euro 3 standards (VCA UK Type Approval #VCA/EMS/5532).
The Citroën RLZ (XU10J4) is a 1,998 cc inline-four naturally aspirated petrol engine designed for mid-size and executive vehicles (1992–2001). It combines multi-point fuel injection with a dual overhead camshaft layout to deliver smooth, linear performance. Engineered to meet Euro 2 and Euro 3 emissions standards, it prioritizes refinement and reliability over high output.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,998 cc | |
| Fuel type | Petrol (Unleaded, 95 RON min) | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 86.0 mm × 85.8 mm | |
| Power output | 99 kW (135 PS) @ 6,000 rpm | |
| Torque | 187 Nm @ 4,000 rpm | |
| Fuel system | Siemens Simos 3P MPFi | |
| Emissions standard | Euro 2 (1992–1996); Euro 3 (1997–2001) | |
| Compression ratio | 10.3:1 | |
| Cooling system | Water-cooled, belt-driven water pump | |
| Turbocharger | Not applicable | |
| Timing system | Timing belt (DOHC) | |
| Oil type | Total Multis 10W-40 | |
| Dry weight | 132 kg |
The naturally aspirated DOHC design provides smooth, linear throttle response ideal for relaxed driving but requires strict adherence to 60,000 km or 5-year timing belt replacement intervals to prevent catastrophic interference engine damage. Total Multis 10W-40 oil is recommended for optimal camshaft and valve train lubrication. Early models (pre-1996) are prone to cam chain tensioner wear under extended oil intervals or frequent short trips; PSA revised the tensioner design and oil pump output in 1996 to improve durability. The Siemens Simos 3P ECU is sensitive to poor-quality fuel, risking long-term injector coking. Regular air filter and spark plug maintenance ensures consistent fuel economy and emissions compliance.
Oil Specs: Requires Total Multis 10W-40 or equivalent meeting PSA B71 2290 specification (PSA SIB-ENG-1998-04).
Emissions: Euro 2 applies to 1992–1996 models; Euro 3 certification applies to 1997–2001 builds (VCA Type Approval #VCA/EMS/5532).
Power Ratings: Measured under ECE R85 standards. Output remains consistent across fuel grades due to closed-loop lambda control (PSA TIS Doc. XU10J4-PERF-01).
PSA Technical Information System (TIS): Docs XU10J4-001, XU10J4-FUEL-01, SIB-ENG-1998-04
VCA Type Approval Database (VCA/EMS/5532)
ISO 1585:1996 Road vehicles — Test code for net power
The Citroën RLZ (XU10J4) was used across Citroën's XM and Xantia platforms with transverse mounting and shared with Peugeot derivatives. This engine received platform-specific tuning—reinforced mounts in the XM and revised intake manifolds in the Xantia—and from 1997 the facelifted Xantia adopted Euro 3-compliant variants with updated ECU mapping, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the right-side cylinder block, near the exhaust manifold (PSA TIS XU10J4-ID-01). The 8th VIN digit indicates engine type ('J' for XU10J4). Pre-1996 models have silver cam covers with ribbed plastic intake manifolds; post-1996 units use black cam covers and smooth intake tracts. Critical differentiation from XU10J2: XU10J4 features Siemens Simos 3P ECU with 80-pin connector and revised valve cover gasket design. Service parts require model-year verification—timing belts and water pumps differ pre- and post-1996 due to revised accessory drive layout (PSA SIB-ENG-1998-04).
The XU10J4's primary reliability risk is cam chain tensioner wear in early production units, with elevated incidence in urban driving cycles. PSA internal quality reports from 1999 indicated a notable number of pre-1996 engines required tensioner replacement before 120,000 km, while UK DVSA MOT records show increased catalytic converter failures linked to lean-running conditions from coked injectors. Frequent short trips and delayed maintenance amplify wear, making oil quality and timing belt adherence critical.
Analysis derived from PSA technical bulletins (1992–2001) and UK DVSA failure statistics (2010–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about CITROEN RLZ-XU10J4.
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