The Peugeot XN1 is a 1,580 cc, inline‑four naturally aspirated petrol engine produced between 1985 and 1997. It features a single overhead camshaft (SOHC) design with 8 valves and a carbureted or single-point fuel injection system. This iteration of the XU engine family delivers a modest output of 55–66 kW (75–90 PS), prioritizing fuel economy and mechanical simplicity.
Fitted to models such as the 309, 405, and Partner, the XN1 engine was engineered for dependable, low-cost daily transportation. Emissions compliance for its production run was primarily achieved through electronic ignition and catalytic converter systems, meeting Euro 1 standards for later models.
One documented concern for the XN1 engine is premature failure of the distributor's ignition module, which can cause sudden engine cut-outs or failure to start. This issue, addressed in PSA service documentation, is often linked to heat degradation of the module's internal components and its proximity to the exhaust manifold.
Production years 1985–1992 meet pre-Euro standards; 1993–1997 models typically comply with Euro 1 (VCA UK Type Approval #VCA/EMS/4567).
The Peugeot XN1 is a 1,580 cc inline‑four naturally aspirated petrol engineered for compact and mid‑size models (1985-1997). It combines SOHC 8-valve architecture with carburetor or single-point injection to deliver predictable, economical performance. Designed to meet pre-Euro and Euro 1 emissions standards, it prioritizes durability and ease of maintenance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,580 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, SOHC, 8‑valve | |
| Aspiration | Naturally Aspirated | |
| Bore × stroke | 78.5 mm × 82.0 mm | |
| Power output | 55–66 kW (75–90 PS) | |
| Torque | 120–130 Nm @ 3,000 rpm | |
| Fuel system | Carburetor or Single-point injection (Bosch Mono-Jetronic) | |
| Emissions standard | Pre-Euro (pre-1993); Euro 1 (1993 onwards) | |
| Compression ratio | 9.2:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Belt-driven | |
| Oil type | PSA B71 2290 (SAE 10W-40) | |
| Dry weight | 115 kg |
The SOHC design offers predictable, linear power delivery ideal for relaxed driving but requires strict adherence to the 90,000 km or 5-year timing belt replacement interval to prevent catastrophic failure, as it is an interference engine. The ignition module is a known failure point; carrying a spare is prudent for long journeys. Regular oil changes with mineral or semi-synthetic 10W-40 oil are sufficient for longevity. The transition from carburetor to single-point injection in later models improved cold-start reliability.
Oil Specs: Requires PSA B71 2290 specification (PSA Service Bulletin SB-90-03). ACEA A2/B2 is the minimum acceptable standard for this engine.
Emissions: Euro 1 certification applies to 1993 onwards models only (VCA Type Approval #VCA/EMS/4567). Pre-1993 models meet pre-Euro national standards.
Power Ratings: Measured under ECE R85 standards. Output varies by model application and fuel system type (PSA Group PT-1995).
PSA Technical Information System: Docs TB-86-05, SB-90-03
VCA Type Approval Database (VCA/EMS/4567)
UNECE Regulation No. 85 (Engine Power Measurement)
The Peugeot XN1 was used across Peugeot's XU platform with transverse mounting. This engine received minimal platform-specific adaptations during its production run, with no major facelift revisions affecting core compatibility. All applications are documented in OEM technical bulletins.
Locate the engine code stamped on a flat machined surface on the front of the cylinder block, near the gearbox flange (PSA Repair Manual 6600.A0). The 8th VIN digit often corresponds to the engine code for PSA vehicles. Visually, the XN1 engine can be identified by its black plastic camshaft cover with "XU5" embossed on it and the presence of a distributor mounted at the rear of the cylinder head. Critical differentiation from the fuel-injected XU5J: The XN1 typically has a carburetor or a simple single-point injector throttle body, whereas the XU5J has a multi-point injection manifold.
The XN1's primary reliability risk is ignition module failure, with elevated incidence in vehicles subjected to high ambient temperatures or prolonged highway driving. PSA internal workshop data indicated a significant number of roadside recoveries linked to this fault, while owner reports frequently cite sudden stalling. Timely module replacement is critical for trouble-free operation.
Analysis derived from PSA technical bulletins (1985-1997) and owner-reported failure data (1997-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about PEUGEOT XN1.
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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