Description and Operation - Engine - Overview

Overview

The 2.3 L GTDI engine can also be described by the following terms:

• GTDI — Gasoline Turbocharged Direct Injection
• DI — Direct Injection
• Ti-VCT — Twin Independent Variable Camshaft Timing
• I4 — 4-cylinder engine
• 16V — 4 valves per cylinder
• 4V — 4 valves per cylinder, 16 valves total

2.3 L GTDI (273 L hp):

• 2.3 L — engine displacement
• 273 L hp — rated engine power

The gasoline 4-cylinder 2.3 L turbocharged direct injection (GTDI) engine has the following characteristics:

• Dual overhead camshafts
• Four valves per cylinder
• Composite intake manifold
• Aluminum cylinder head
• Aluminum cylinder block
• Twin Independent Variable Camshaft Timing (Ti-VCT)
• External cooled EGR

Engine Identification

Always refer to these labels when installing new parts or when verifying engine calibration. Engine parts often differ within the same engine family. Checking the identification codes will ensure that the correct parts are obtained. These codes contain all relevant information regarding dates, optional equipment and changes.

Engine Code Label

Engine Cylinder Identification

Oil flow diagram

For more detailed information on the oil flow diagram, refer to

Lubrication System

The engine lubrication system is a pressure feed system. Oil is supplied at full pressure to the crankshaft, connecting rod bearings, timing chain tensioners, camshaft bearing caps and VCT solenoids. Oil flow to the valve lifters and valve train is controlled by a restrictor orifice located in the cylinder head gasket.

The lubrication system is designed to provide optimum oil supply to critical engine components over the entire operating range.

The heart of the system is a variable displacement vane-type oil pump, controlled by an oil pressure control solenoid valve.

In general, this design operates as follows:

• The maximum displacement of the oil pump was selected to provide sufficient volume to deliver the required pressure both at hot idle and at maximum engine speed.
• An internal relief valve protects the system from excessive pressure during high oil viscosity conditions. When activated, it returns excess oil to the oil pan.
• Under conditions other than hot idle and maximum speed, oil flow and pressure are controlled by the oil control solenoid valve, which receives commands from the powertrain control module (PCM), to deliver the correct oil pressure for all operating conditions based on engine speed, load and oil temperature.
• The oil control solenoid valve regulates oil pump output by controlling oil pressure in the internal control chamber of the oil pump.

Ti-VCT

The Ti-VCT system provides variable valve control that optimizes full-load combustion, increasing power and torque at low engine speeds (broadening the torque curve). By changing valve overlap, it improves fuel economy and emissions and provides optimized cold start operation with reduced exhaust emissions.

Valvetrain

The valvetrain uses direct acting mechanical bucket tappets (DAMB). The camshaft lobes are located directly above the mechanical bucket tappets, which are located above the valves.