Engine. Description and Operation

Overview

The 1.6 L 4-cylinder GTDI engine has the following characteristics:

• Dual overhead camshafts
• Four valves per cylinder
• Composite intake manifold
• Aluminum cylinder head
• Aluminum cylinder block
• Gasoline Turbocharged Direct Injection (GTDI)
• Twin Independent Variable Cam Timing (Ti-VCT)

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

The engine code identification label, located on the front face of the timing cover, contains the following:

Engine Cylinder Identification

System Operation

Lubrication System

The engine lubrication system is a pressure feed system. Oil is supplied under full pressure to the crankshaft, connecting rod bearings, camshaft bearing caps and VCT solenoids. Oil supply to the valve lifters and valvetrain 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 positive displacement internal gear oil pump.

This design is commonly known as a variable displacement oil pump or vane-type pump, which operates as follows:

• The oil pump is driven by the crankshaft.
• System pressure is limited by an integral, internally vented relief valve that returns bypassed oil to the oil pump inlet side.
• Oil pump capacity is selected to provide sufficient flow to ensure correct oil pressure at hot idle and at maximum engine speed.
• Relief valve calibration protects the system from excessive pressure under high oil viscosity conditions.
• The relief valve is designed to ensure adequate connecting rod bearing lubrication under high temperature and high speed conditions.

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.

Twin Independent Variable Cam Timing (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.