Ford Mondeo Workshop Service and Auto Repair Manuals

The L-shaped valve cover is made from composite material.

The PCV valve is integrated in the valve cover

A flat gasket is used to form a seal between the valve cover and the upper part of the cylinder head. The PCV components are sealed by two O-rings in the upper part of the cylinder head.

PCV

Cylinder head

NOTE:The upper and lower parts of the cylinder head are matched to each other in terms of tolerances and must not be renewed as individual parts.

NOTE:The parts of the cylinder head must not be reworked.

Both cylinder head parts have been matched to each other during production. Two guide sleeves position the cylinder head parts exactly.

The upper part of the cylinder head is bolted to the lower part of the cylinder head and sealed as follows:

• using silicon sealer (seals the outer area),
• using a ready-made gasket (seals the swirl ducts and the guides for the fuel injectors).

The upper halves of the camshaft mountings are incorporated into the upper part of the cylinder head. The camshafts run directly in the aluminium.

The camshafts are made from cast iron. The intake camshaft drives the vacuum pump at the rearward end. The exhaust camshaft drives the fuel pump at the rearward end. An O-ring provides the seal in each case.

The lower part of the cylinder head is bolted to the cylinder block with a total of 10 bolts. The old cylinder head bolts may not be reused during servicing.

Cylinder head gasket

The multi-layer steel cylinder head gasket is available in four thicknesses depending on the piston protrusion.

Camshaft and camshaft drive

Overview of the components

Timing Cover

The plastic timing covers are secured to the engine using a total of nine bolts.

There is a hole (arrow) in the upper timing cover. This hole permits the insertion of the special tool for securing the exhaust camshaft pulley. This allows fast checking of the valve timing.

Camshaft Drive

The exhaust camshaft is driven by the crankshaft via a timing belt.

The intake camshaft is driven by the exhaust camshaft via a timing chain.

Pretensioning of the timing chain is performed by a hydraulic timing chain tensioner.

Hydraulic timing chain tensioner

The hydraulic timing chain tensioner is mounted between the camshaft sprockets on the upper part of the cylinder head.

The hydraulic chain tensioner is supplied with the appropriate oil pressure via an oil bore. Also integrated in the hydraulic timing chain tensioner is a compression spring. This ensures the necessary pretensioning of the drive chain.

There is a service pin at the chain tensioner for releasing the pretension during servicing.

Locking and disengaging the hydraulic timing chain tensioner

NOTE:After installing the upper part of the cylinder head, make sure that the hydraulic chain tensioner is in the disengaged position.

The chain tensioner can be locked and disengaged again for servicing using the service pin.

To lock the chain tensioner, lift the service pin and then turn it 90 degrees.

To pretension the chain tensioner, turn the service pin once more by 90 degrees. The unlocking can be clearly felt.

Cylinder block

NOTE:Cylinder 1 is located on the transaxle side of the engine.

The cylinder block is made from grey cast iron and is double-walled. This helps to achieve high strength. It also forms a blanket of air that results in considerable sound insulation.

The serial number of the engine and the engine code are located on the intake side of the cylinder block (in line with the second cylinder).

The running surfaces of the cylinders are worked directly into the cylinder block.

There are two holes on the cylinder block for the guide bushings for securing the cylinder head gasket and the cylinder head.

Oil Spray Jets

The efficient combustion provided by the direct-injection turbocharged diesel engine means that high temperatures are transmitted to the pistons.

There is an oil spray nozzle installed at the lower end of each cylinder liner for cooling the pistons. The oil spray nozzles spray engine oil in a targeted manner under the piston crowns.

There are oil passages integrated in the piston crowns. The sprayed engine oil enters these oil passages and thus ensures the necessary piston cooling. Piston cooling is not essential when the engine is cold. Lubrication of the crank gear and camshaft has a higher priority here. For this reason, the oil spray nozzles only open if an oil pressure of more than 0.5 bar is present at them.

Cylinder block extension

The oil pan extension is fitted between the cylinder block and the oil pan.

The use of balance shafts means that the oil pump has to be moved further in the direction of the oil pan. This reduces the distance from the oil pump to the oil pan. The cylinder block extension at the cylinder block re-establishes the distance between the oil pump and oil pan.

The seal with the cylinder block and the oil pan is formed using sealing compound.

Crankshaft and main bearings

The crankshaft runs on five bearings by means of five main bearing caps.

Each main bearing half cap is stamped with the corresponding cylinder number for identification.

The crankshaft's radial play is restricted by four semicircular thrust washers that are arranged on either side of main bearing 2.

Lubrication grooves are formed on the thrust washers and must face toward the main bearing.

Each main bearing housing and half cap contains an upper and lower bearing half shell manufactured from aluminum/tin. The upper half shells are formed with a drilling and annular groove to transfer pressurized oil from the main bearing, through crankshaft drillings to the connecting rod big-end bearings.

For establishing the correct crankshaft main bearing play, the lower main bearing shells are available in five different thicknesses.

The balance shaft drive gear is shrunk onto the third crankshaft web. The helical drive gear provides the drive for the balance shafts.

Piston and Connecting Rod Assembly

Connecting rods

The connecting rods are made from forged steel.

The connecting rod small-end is narrowed on each side to form a tapered head. The taper improves the distribution of force between the piston and connecting rod during the combustion stroke.

A bronze bush is installed in the small-end, and formed with an internal groove to allow the flow of lubricating oil around the bush.

Connecting rod big-end

The connecting rod large end is split as a bearing housing. The bearing cap is mounted using two bolts.

The connecting rod size is engraved both on the connecting rod large end and on the bearing cap to denote that the components belong together.

There is a bearing shell mounted in the connecting rod large end and in the bearing cap.

The connecting rod large end, the bearing cap and the bearing shells have a lug that aligns the bearings in the housings and prevents radial movement of the bearing shells. During installation the lugs must face toward the LH side (oil filter side) of the engine.

Pistons

The pistons are made from an aluminium alloy and have a total of three piston rings.

A steel insert is installed in the piston upper ring groove to provide reinforcement.

A piston recess of typical design for direct diesel injection is incorporated into the piston crown.

Recesses are also formed in the piston crown to provide clearance for the 4 valve heads. This type of combustion chamber design produces optimum air/fuel mixture swirl.

The 3 piston rings must be installed with the ring gaps spaced at 120° (with permissible tolerance of 15° to 20°) to each other, around the piston.

The 2 upper compression rings are stamped with 'top' to aid installation.

The bearing surface of the piston is finished with a graphite substance for reducing friction in the cylinder bore.

Two oil cooling channels on the underside of the piston crown ensure optimum piston cooling.

Balance shaft unit

NOTE:The balance shaft unit must not be dismantled during servicing.

NOTE:Before installing the balance shaft unit, the backlash between the two balance shafts must be checked.

The balance shaft unit contains two balance shafts and is arranged beneath the crankshaft.

The assembly is attached with 8 bolts to the bottom of the cylinder block.

The oil pump is arranged on the underside of the balance shaft housing (not illustrated).

The balance shaft unit is attached to the cylinder block extension using two shims and eight bolts.

The backlash between the propelled balance shaft and the balance shaft drive gear at the crankshaft is determined using the shims.

The balance shafts should counteract the different forces of inertia (caused by the countermovement of the piston pair) at the crankshaft.

Operation

The balance shaft drive gear at the crankshaft propels the propelled balance shaft in the opposite direction of rotation to the crankshaft.

The driven balance shaft is propelled by the propelled balance shaft and rotates in the same direction as the crankshaft.

The balance shaft drive gear at the crankshaft has twice as many teeth as the mating gears on the two balance shafts. The gear ratio is therefore 1:2.

Oil Pump Assembly

The oil pump is designed as a rotor pump and is bolted to the balance shaft unit using four retaining bolts. A further bolt at the oil strainer secures the oil pump with the oil dipstick tube.

The drive is provided by the crankshaft via a Simplex chain.

The oil pump generates a maximum permissible oil pressure of approx. 6.5 bar and a maximum delivery rate of 50 l/min.

A pressure relief valve within the oil pump outlet protects the oil pump and lubrication system components from system over-pressure.

The pressure relief valve opens at approx. 8 bar. The excess oil runs directly back into the oil pan.

Oil filter/oil cooler unit

The oil filter/oil cooler unit is located on the intake side of the engine, level with the third cylinder.

The oil filter element (paper filter element) is located in the oil filter housing.

The coolant is routed from the cylinder block into the oil cooler via the coolant feed. The coolant is routed to the thermostat housing of the cooling system via the coolant return.

A thermostat is integrated in the oil filter/oil cooler housing. The thermostat controls the amount of engine oil flowing through the oil cooler as a function of the engine oil temperature.

Intake manifold

The intake manifold is designed so that the charge air is routed to all eight intake ducts in a controlled manner.

Furthermore, the gas from the positive crankcase ventilation system and from the EGR (exhaust gas recirculation) system is returned to the intake manifold.

The seal with the intake ducts at the cylinder head is provided:

• by means of one O-ring for each of the four lower swirl ducts,
• by means of one rubber seal for each of the four upper charge ducts.

Note: When fitting the intake manifold, ensure that the O-rings/rubber seals are seated correctly.

The intake manifold is bolted to the cylinder head using a total of seven retaining bolts.

Intake ducts

The movement of the air flowing into the cylinder is crucial for optimum mixture formation.

Each cylinder is equipped with two intake valves. Leading to each intake valve is

• one swirl duct and
• one charge duct.

The swirl duct produces a specific rotational movement (swirl) in the charge air. This optimises mixture formation in the lower engine speed range and thus reduces fuel consumption.

The charge duct guarantees an optimum cylinder charge at all times. This has a positive effect on engine performance in the upper engine speed range.

Exhaust Manifolds

The exhaust manifold is bolted to the cylinder head using nine studs with self-locking nuts.

There is also a spacer mounted over each stud. The spacers compensate the expansion play when the exhaust manifold heats up or cools down.

One connecting flange each is incorporated in the exhaust manifold for the TC and the EGR.

There is an exhaust manifold heat shield mounted over the exhaust manifold (not illustrated). This protects heat-sensitive components in the vicinity of the exhaust manifold. It also prevents burns if someone accidentally touches the exhaust parts.

TC

Charging of the engine takes place via the TC from Garrett with variable turbine geometry.

The turbocharger variable vanes are adjusted by a turbocharger variable vane electrical actuator.

The shaft of the TC is lubricated and/or cooled with engine oil via a supply line.

The TC can reach a shaft speed of up to 200,000 rpm during operation.

A charge pressure of almost 1.7 bar is achieved depending on the engine speed and engine load.

EGR system

Overview of the components

Diesel engines work with a large surplus of air. The high proportion of O2 (oxygen) produces a high proportion of NOX (oxides of nitrogen) during combustion.

Via the EGR system, part of the exhaust gas is routed back into the fresh air flow.

The proportion of recirculated exhaust gas no longer directly participates in the combustion. This significantly reduces the proportion of NOX.

The exhaust gas recirculation rate depends to a large extent on the engine speed and engine load. The exhaust gas can be recirculated particularly efficiently in the lower partial load range. Recirculation rates of over 60% are possible under favourable conditions.

EGR valve and radiator

The EGR valve consists of a DC (direct current) motor and a position sensor.

The EGR valve and the EGR radiator are bolted together.

The EGR radiator is connected to the coolant circuit.

The EGR cooling reduces the NOX emission.

Accessory drive