Engine: Description and Operation

Ford does not provide camshaft gear timing marks, or information to perform timing belt service without the special tools shown in the timing belt service and repair procedure. Timing Belt








The 2.0L Zetec-VCT engine is a four cylinder in-line engine with double overhead camshafts and 16 valves. The 16 valve cylinder head improves volumetric efficiency, particularly at high engine speeds. The 2.0L engine has variable camshaft timing.
The cylinder head is made of aluminum alloy and the cylinder block is made of cast iron.

Timing Belt Center Cover/Engine Front Mounting Bracket:

The new timing belt cover has a vertical strengthening rib for additional reinforcement. As a result of this, the center timing belt cover (and therefore the front engine mounting) has to be removed in order to replace the timing belt.
The spark plug is installed in the center of the roof-shaped combustion chamber to ignite the air/fuel mixture in the combustion chamber. The central location of the spark plug causes the flame front to be evenly spread across the combustion chamber, which also reduces spark knock.
Both camshafts are driven by a shared timing belt, and operate four valves per cylinder by means of adjustable tappets. The exhaust valves are subjected to extremely high temperatures as a result of the exhaust gases flowing past them. In order to conduct the heat away from the valve heads, the exhaust valves are impregnated with sodium. One spring on each valve is used to close the valve. The spring on the exhaust valve is marked with a blue paint mark, and the spring on the intake valve with a red one. The adjusting shims in the valve tappets can be changed to correct the valve clearance. These are available in 52 different thicknesses. The shim thickness is stamped on the back of the shim in hundredths of a millimeter (Example: the number 222 means 2.22 mm). Because of space limitations the camshafts have to be removed before the adjusting shims can be replaced. This means that a high degree of accuracy is required during adjusting to avoid repeated removal and installation of the camshafts. The camshaft cams run concentrically on the valve tappets. At engine speeds of above about 3000 rpm the tappets rotate, and they in turn transfer the rotation to the valves. This valve rotation is desirable because it produces an even valve seating and prevents the valves from wearing in a certain position which could cause them to leak.









CAUTION: Only tension the timing belt counter-clockwise.

NOTE: Always replace the timing belt after loosening/removing it.

An automatic timing belt tensioner ensures the proper timing belt tension. An additional spring-loaded cam provides proper belt tension during operation. The belt tensioner can operate 30� either side of its central position.
The basic adjustment of the belt tensioner can no longer be controlled after the aligning tools and adjusting pin have been taken out (the spring forces from the valve train exert pressure on the timing belt and alter the position of the belt tensioner).








The use of the new variable camshaft timing optimizes the combustion procedure by improving gas exchange in the cylinders. As a result of this the exhaust emissions regulations can be met without the use of a pulse air system or an exhaust gas recirculation system (EGR system).
The mechanical principles behind variable camshaft timing (VCT) are relatively simple. The valve timing for opening and closing of the exhaust valves is influenced by a hydraulic cylinder (3) which is riveted to the timing pulley (1). This cylinder connects the timing pulley (1) with the camshaft (8) through a hydraulic piston (4). The hydraulic piston is guided along its axis by the helical gears (6,7) on the exhaust camshaft and the hydraulic cylinder. The helical gear transfers the up and down motion of the hydraulic piston into a rotary motion. As the timing pulley is fixed in place by the timing belt, the position of the exhaust camshaft is rotated in relation to the timing pulley, and the exhaust valve timing is therefore adjusted. The hydraulic piston is moved by supplying pressurized engine oil from the engine oil circuit to both pressure chambers of the hydraulic cylinder. The engine management system controls a solenoid valve which in turn supplies the pressurized oil to the pressure chambers.
The return spring (3) ensures that the hydraulic piston goes back towards its original position when the engine is switched off.

Variable Camshaft Timing (VCT) Unit In Original Position And At Maximum Extension, Part 2 Of 3:

Variable Camshaft Timing (VCT) Unit In Original Position And At Maximum Extension, Part 3 Of 3:

The VCT unit is supplied with engine oil (3) From the engine oil circuit and controlled by the engine management systems. To do this the engine management system alters the current of the regulated DC voltage applied to the solenoid valve (2).
With rising current of 0 to 1, the displacement of the control piston (4) in relation to the return spring (6) increases, and vice versa. As a result of this motion the control edge and return bores (5) of the control piston open and close the oil flow to and from the two pressure chambers (11,12) of the hydraulic cylinder(9).
When the engine is switched off the return spring returns the control piston back to its original position. At the same time the return bores in the front pressure chamber (12) are opened, which allows the return spring (12) to slide back the position in the hydraulic cylinder towards its original position.





The Hydraulic piston can be infinitely adjusted in the hydraulic cylinder. However, the control piston can only move into three positions.
- Pos. 1: Original position (0 Ampere)-return bores in the front pressure chamber and feed line to rear pressure chamber are open (hydraulic piston moves to or remains in original position-exhaust valves open and close early).
- Pos. 2: Intermediate position (0.6 Ampere)-all return bores and feed lines are closed (hydraulic piston is held in the position it was previously moved to).
- Pos. 3: End position (1 Ampere)-retun bores in the rear pressure chamber and feed line to front pressure chamber are open (hydraulic piston moves to or remains at maximum extension-valves open and close late).

When the engine is switched off the VCT unit is non-pressurized and therefore has no function.
However, the hydraulic piston usually only returns right back to the original position if the VCT unit has been removed or the engine was switched off. A complete return to the original position is prevented by friction on the cams and the spring forces due to the valve springs.
The VCT unit must be in its original position before the valve timing can be adjusted. Turn the exhaust camshaft in the normal direction of engine rotation to bring the VCT unit to its original position. When doing this the crankshaft must not be turned.

Installation Position-Oil Feed Ring/Camshaft:

The oil bores of the oil feed ring and the timing pulley form a labyrinth on three levels. The oil bore of the oil feed ring and the two oil bores (1) on the hydraulic cylinder (one visible) are arranged at 120 degrees to each other. This prevents the hydraulic cylinder from running dry when the engine is switched off. This means that the VCT unit is ready to work shortly after starting the engine.
The lug (2) must be centered between the two oil bores and the mark - if this is not the case replace the exhaust camshaft timing pulley and the hydraulic cylinder. The lug (2) must locate in the bore when sliding the timing pulley onto the oil feed ring.
The 2.0L Zetec-VCT engine is equipped with a glass fiber reinforced plastic intake manifold. The intake manifold ports are designed so that the intake paths are the same length for all the cylinders.
- This gives the following advantages:
- reduced heat transfer to the injectors, thereby avoiding vapor locks
- lighter weight
- reduction of fuel deposits on the intake walls during cold starts
- less heating of the intake air when the engine is hot.

Oil Feed Flange Gasket (3 X O-Ring Seal):

The oil feed flange gasket needs to be replaced every time the oil feed flange is disassembled. Proper seating of the gasket ensures that the oil feed flange seals properly and lies properly on the sealing face (incorrect seating, can cause tilting).
The crankshaft runs on five bearings and has a counterweight for each cylinder. The central main bearing has two bearing half shells which guide the crankshaft along its axis as well as adjusting the end float.









The connecting rods are numbered 1 to 4, starting at the timing belt end. It is almost impossible to mix up the big-end bearing caps and connecting rods, because they are forged as a unit in production and then broken apart. The join between each big-end bearing cap and connecting rod is therefore unique.

View Of Lower Crankcase:

The EEC V module manages the 2.0L Zetec-VCT engine. The module requires a large amount of information about the current operating conditions of the engine and, where appropriate, the automatic transmission (CD4E). The EEC V module obtains this information by means of sensors.

The EEC V module controls:
- the variable camshaft timing (VCT) unit
- the fully electronic ignition system (EI)
- the sequential electronic fuel injection system (SEFI)
- the air conditioning system together with the cooling system.
- the transmission control for the CD4E automatic transmission.

The purpose of the lower crankcase is to reduce engine vibrations. This further reduces the level of noise inside the vehicle. There is a rubber gasket between the lower crankcase and the cylinder block.

Lower Crankcase Spacer Shims:

Lower crankcase spacer shims are used to even out any excessively large gaps between the transmission and the lower crankcase (see Specifications).
The engine is closed off at the bottom with a pressed steel oil pan which is directly attached to the lower crankcase. It is sealed with a 3 mm wide bead of sealer.
Lower crankcase spacer shims are used to even out any excessively large gaps between the transmission and the lower crankcase (see Specifications).
The engine is closed off at the bottom with a pressed steel oil pan which is directly attached to the lower crankcase. It is sealed with a 3 mm wide bead of sealer.