Citroen TU3F2K engine schematics

Posted by

Introduction to the Citroen TU3F2K Engine

The Citroen TU3F2K is a 1.4-liter, inline-4 gasoline engine that was produced by the French automaker Citroen from 1998 to 2006. This engine was used in various Citroen models, including the Saxo, Xsara, and C3. The TU3F2K is part of the TU engine family, which was introduced in 1986 and underwent several updates and improvements over the years.

Key Features of the Citroen TU3F2K Engine

  • Displacement: 1,360 cc (83.0 cu in)
  • Bore × Stroke: 75.0 mm × 77.0 mm (2.95 in × 3.03 in)
  • Compression Ratio: 10.2:1
  • Valvetrain: SOHC, 8 valves
  • Fuel System: Multi-point fuel injection
  • Power Output: 75 PS (55 kW; 74 hp) at 5,500 rpm
  • Torque Output: 120 N⋅m (89 lb⋅ft) at 3,400 rpm

TU3F2K Engine Block and Cylinder Head

The Citroen TU3F2K engine features a cast-iron block with aluminum alloy cylinder head. The block is designed to provide excellent durability and heat dissipation, while the lightweight cylinder head contributes to the engine’s overall efficiency.

Cylinder Block Specifications

Specification Value
Material Cast Iron
Bore Diameter 75.0 mm (2.95 in)
Deck Height 201.5 mm (7.93 in)
Main Bearing Caps 4-bolt, forged steel

Cylinder Head Specifications

Specification Value
Material Aluminum Alloy
Valve Configuration SOHC, 8 valves
Combustion Chamber Design Wedge-shaped
Valve Angle 20 degrees

Crankshaft, Pistons, and Connecting Rods

The TU3F2K engine uses a forged steel crankshaft, aluminum alloy pistons with graphite-coated skirts, and forged steel connecting rods. These components are designed to withstand the stresses of high-speed operation while minimizing friction and wear.

Crankshaft Specifications

Specification Value
Material Forged Steel
Main Journal Diameter 48.0 mm (1.89 in)
Rod Journal Diameter 42.0 mm (1.65 in)
Stroke 77.0 mm (3.03 in)

Piston Specifications

Specification Value
Material Aluminum Alloy
Skirt Coating Graphite
Compression Height 29.5 mm (1.16 in)
Piston Pin Diameter 20.0 mm (0.79 in)

Connecting Rod Specifications

Specification Value
Material Forged Steel
Length (Center-to-Center) 133.0 mm (5.24 in)
Big End Bearing Type Tri-metal, Removable

Valvetrain and Camshaft

The Citroen TU3F2K engine employs a single overhead camshaft (SOHC) valvetrain with 8 valves (2 valves per cylinder). The camshaft is driven by a timing belt, which also drives the water pump and oil pump.

Camshaft Specifications

Specification Value
Material Chilled Cast Iron
Drive Type Timing Belt
Bearing Type Aluminum Alloy, Removable
Intake Valve Lift 8.2 mm (0.32 in)
Exhaust Valve Lift 8.2 mm (0.32 in)

Valve Specifications

Specification Intake Exhaust
Head Diameter 33.0 mm (1.30 in) 29.0 mm (1.14 in)
Stem Diameter 6.0 mm (0.24 in) 6.0 mm (0.24 in)
Valve Spring Type Coil, Single Coil, Single

Fuel System and Ignition

The TU3F2K engine uses a multi-point fuel injection system, which delivers fuel to each cylinder through individual injectors. The ignition system features a distributorless ignition with individual ignition coils for each spark plug.

Fuel System Components

  • Fuel Injectors: 4, top-feed, 190 cc/min flow rate
  • Fuel Pressure Regulator: 3.0 bar (43.5 psi)
  • Throttle Body: 55 mm (2.17 in) diameter, electronically controlled

Ignition System Components

  • Ignition Coils: 4, pencil-type, mounted on spark plugs
  • Spark Plugs: NGK BKR6E-11, 1.0 mm (0.039 in) gap
  • Ignition Timing: 10 degrees BTDC at idle, electronically controlled

Lubrication and Cooling Systems

The Citroen TU3F2K engine features a pressure-fed lubrication system with a gear-type oil pump driven by the crankshaft. The cooling system is a liquid-cooled design with a centrifugal water pump driven by the timing belt.

Lubrication System Specifications

Specification Value
Oil Pump Type Gear
Oil Pressure (at idle) 1.0 bar (14.5 psi)
Oil Pressure (at 3,000 rpm) 4.0 bar (58.0 psi)
Oil Capacity (with filter) 3.5 liters (3.7 US qt)

Cooling System Specifications

Specification Value
Coolant Capacity 5.0 liters (5.3 US qt)
Thermostat Opening Temperature 88°C (190°F)
Radiator Cap Pressure 1.4 bar (20.3 psi)


The Citroen TU3F2K engine is a reliable and efficient powerplant that served various Citroen models from 1998 to 2006. With its robust design, multi-point fuel injection, and advanced ignition system, the TU3F2K provided a balance of performance and fuel economy for compact vehicles.

Frequently Asked Questions (FAQ)

1. What is the recommended oil viscosity for the Citroen TU3F2K engine?

The recommended oil viscosity for the TU3F2K engine is 5W-30 or 10W-40, depending on the ambient temperature conditions. Always refer to the owner’s manual for the most accurate information.

2. How often should the timing belt be replaced on the TU3F2K engine?

Citroen recommends replacing the timing belt on the TU3F2K engine every 120,000 km (75,000 miles) or 10 years, whichever comes first. It is crucial to adhere to this maintenance schedule to prevent potential engine damage.

3. What is the firing order of the Citroen TU3F2K engine?

The firing order of the TU3F2K engine is 1-3-4-2.

4. Can I use aftermarket parts when servicing my TU3F2K engine?

While aftermarket parts may be available for the TU3F2K engine, it is recommended to use genuine Citroen or OEM-equivalent parts to ensure optimal performance and longevity.

5. What are some common issues with the Citroen TU3F2K engine?

Some common issues reported by owners of vehicles with the TU3F2K engine include:
– Timing belt tensioner failure
– Oil leaks from the valve cover gasket or oil pan gasket
– Idle air control valve (IACV) malfunction
– Exhaust gas recirculation (EGR) valve clogging

Regular maintenance and prompt attention to any warning signs can help prevent or mitigate these issues.