The Peugeot XK4 is a 1,288 cc, inline‑four naturally aspirated petrol engine produced between 1972 and 1985. It features a single overhead camshaft (SOHC), 8 valves, and a carbureted fuel system. In standard specification, it delivered approximately 55 kW (75 PS) and 102 Nm of torque, offering adequate performance for its lightweight applications.
Fitted primarily to the 104 and early 205 models, the XK4 engine was engineered for economical, lightweight city cars, pri…
Production years 1972–1985 pre-date formal Euro emissions standards. Compliance was based on national regulations of the era (no VCA Type Approval applicable).
The Peugeot XK4 is a 1,288 cc inline‑four naturally aspirated petrol engine engineered for supermini applications (1972-1985). It combines a simple SOHC 8-valve architecture with a single-barrel carburetor to deliver economical, predictable performance. Designed for an era before stringent emissions regulations, it prioritizes mechanical simplicity and ease of repair.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,288 cc | |
Fuel type | Petrol | |
Configuration | Inline‑4, SOHC, 8‑valve | |
Aspiration | Naturally Aspirated | |
Bore × stroke | 74.0 mm × 75.0 mm | |
Power output | 55 kW (75 PS) @ 5,800 rpm | |
Torque | 102 Nm @ 3,500 rpm | |
Fuel system | Single-barrel carburetor (Solex or Weber) | |
Emissions standard | Pre-Euro (National Regulations) | |
Compression ratio | 9.3:1 | |
Cooling system | Water‑cooled | |
Turbocharger | None | |
Timing system | Chain-driven (camshaft) | |
Oil type | API SF/CC (e.g., SAE 15W-40) | |
Dry weight | 98 kg |
The Peugeot XK4 was used across Peugeot's A platform with transverse mounting. This engine received platform-specific adaptations-reinforced engine mounts in the 205 and revised carburetor linkages for the 104 ZS. All adaptations are documented in OEM technical bulletins.
The XK4's primary reliability risk is distributor drive gear wear, with elevated incidence in high-mileage, early-production units. Peugeot technical bulletins document this issue, while general owner reports highlight carburetor issues as a common secondary concern. Adherence to correct maintenance and using quality replacement parts is critical for mitigating these risks.
Analysis derived from Peugeot technical bulletins (1978-1982) and historical service data. Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The XK4 engine is fundamentally robust and simple, making it potentially very reliable with basic maintenance. The key known issue is the distributor drive gear on early units, which should be replaced with the hardened version if worn. Regular oil changes and carburetor servicing are essential for longevity. Many examples have exceeded 200,000 km with proper care.
The most common issues are wear of the distributor drive gear (on early units), various carburetor problems (float, jets, choke), oil leaks from the rear main seal, and coolant leaks from the water pump. These are well-documented in Peugeot service information and are typical of engines from this era.
This 1.3L petrol engine was used in the Peugeot 104 (1972-1983) and the very early Peugeot 205 (1983-1985). It was the base engine for the 104 and was quickly superseded by larger displacement engines in the 205 range.
Modest gains are possible. Fitting a performance carburetor (e.g., twin-choke Weber), a free-flow exhaust, and a modified distributor can yield around 10-15% more power. More significant gains are limited by the engine's basic SOHC design. Reliability should be the priority, as these are now classic engines.
Real-world fuel economy is good for its era. In a Peugeot 104, expect around 7.0-8.5 L/100km (33-40 mpg UK) in mixed driving. Highway cruising can see figures closer to 6.0-6.5 L/100km (43-47 mpg UK). City driving will be higher, around 9.0-10.0 L/100km (28-31 mpg UK).
No. The XK4 is a non-interference engine. If the timing chain were to fail or jump significantly, the pistons would not contact the open valves, preventing catastrophic internal engine damage. The engine would simply stop running until the chain is replaced.
Peugeot originally specified an oil meeting API SF/CC standards. A 15W-40 or 20W-50 viscosity grade mineral or semi-synthetic oil is typically recommended for engines of this vintage. Using a quality oil helps protect the engine's internals, particularly the camshaft and distributor drive gear.
Comprehensive technical documentation and regulatory references
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PEUGEOT Official Site
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EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
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