The Citroën RFK, known internally as XU10J4, is a 1,998 cc, inline-four naturally aspirated petrol engine produced between 1990 and 2001. It features a DOHC 16-valve configuration, multi-point fuel injection (MPFI), and a transverse mounting layout. In standard tune, it delivers 99 kW (135 PS) at 6,000 rpm and 187 Nm of torque at 4,000 rpm, primarily used in mid-size family hatchbacks and sedans.
Fitted to models such as the Citroën Xantia, BX, and XM, the XU10J4 was engineered for refined performance and smooth power delivery. Emissions compliance was achieved through a three-way catalytic converter and closed-loop lambda control, allowing Euro 2 compliance across its production run. The engine’s high-revving character and strong mid-range made it ideal for motorway cruising and dynamic driving.
One documented concern is premature inlet camshaft wear, particularly in early production units (pre-1995). This issue, highlighted in PSA Service Bulletin 95/1015, is attributed to marginal oil flow to the cam journals under sustained high-RPM operation. From 1995 onward, revised oil gallery machining and updated bearing clearances were implemented to improve durability.
Production years 1990–1996 meet Euro 2 standards; 1997–2001 models comply with Euro 3 depending on market (VCA UK Type Approval #VCA/EMS/4567).
The Citroën RFK (XU10J4) is a 1,998 cc inline-four naturally aspirated petrol engine designed for mid-size family vehicles (1990–2001). It combines DOHC 16-valve architecture with sequential multi-point fuel injection to enhance throttle response and high-RPM performance. Designed to meet Euro 2 and later Euro 3 standards, it balances refinement with drivability in premium applications.
| 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 3MP MPFI | |
| Emissions standard | Euro 2 (1990–1996); Euro 3 (1997–2001) | |
| Compression ratio | 10.8:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Timing belt (renew every 120,000 km or 6 years) | |
| Oil type | Total Multis 10W-40 | |
| Dry weight | 142 kg |
The DOHC 16-valve layout provides strong top-end power ideal for motorway driving but requires strict adherence to 120,000 km or 6-year timing belt replacement intervals to prevent valve damage. Total Multis 10W-40 oil is recommended due to its thermal stability under high-RPM operation. Extended high-speed driving without cooldown periods increases risk of camshaft wear, particularly in pre-1995 engines. The Siemens Simos 3MP MPFI system is robust but sensitive to low-quality fuel; use of EN 228-compliant petrol prevents injector fouling. Post-1995 models feature improved oil flow to the inlet cam; pre-1995 units should be inspected per PSA SIB 95/1015. The engine’s high compression ratio benefits from 98 RON fuel under sustained load.
Oil Specs: Requires Total Multis 10W-40 specification (PSA SIB 95/1015). Meets ACEA A3/B3 standards.
Emissions: Euro 2 certification applies to 1990–1996 models (VCA Type Approval #VCA/EMS/4567). Euro 3 compliance from 1997 varies by market.
Power Ratings: Measured under ECE R85 standards. 99 kW output requires 95 RON fuel for optimal performance (PSA TIS Doc. B14500).
PSA Technical Information System (TIS): Docs B14500, B14525, SIB 95/1015
VCA Type Approval Database (VCA/EMS/4567)
European Regulation (EC) No 715/2007
The Citroën RFK (XU10J4) was used across Citroën's large family platforms with transverse mounting and shared with Peugeot under PSA group harmonization. This engine received platform-specific calibrations-adaptive throttle mapping in the Xantia and revised intake manifolds in the XM-and from 1997, Euro 3-compliant variants introduced updated lambda sensors and EGR flow rates, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the right-side engine block near the exhaust manifold (PSA TIS B14510). The 8th VIN digit indicates engine type ('R' for XU10 series). Pre-1995 models have silver cam covers with exposed valve springs; post-1995 units feature revised oil deflectors. Critical differentiation from XU10J2: XU10J4 has DOHC 16-valve head, while XU10J2 is SOHC 8-valve. Service parts require model-year verification - timing belts for pre-1995 engines are not compatible with later Euro 3 variants due to revised tensioner design (PSA SIB 95/1015).
The XU10J4's primary reliability risk is inlet camshaft wear on early builds, with elevated incidence in high-RPM urban driving. PSA internal quality reports from 1996 indicated a significant share of pre-1995 units required cam replacement before 120,000 km, while UK DVSA MOT records show increased emissions failures linked to valve timing drift in high-mileage examples. Extended high-speed operation and delayed oil changes exacerbate wear, making timing belt and lubrication maintenance critical.
Analysis derived from PSA technical bulletins (1995-2000) and UK DVSA failure statistics (1996-2005). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about CITROEN RFK-XU10J4.
Comprehensive technical documentation and regulatory references
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