SECTION 303-01D: Engine — 2.3L
2003 Focus Workshop Manual
DESCRIPTION AND OPERATION
Procedure revision date: 01/24/2003

Engine

The 2.3L engine is a four valve-per-cylinder, dual overhead camshaft engine. The engine uses a coil-on-plug ignition system. The cylinder block is made of aluminum and the bearing caps are integrated into the ladder assembly. An aluminum oil pan bolts to the bottom of the lower cylinder block and to the transmission to provide greater strength. The camshafts are mounted in the cylinder heads and act against valve tappets to open and close the valves. The camshafts are driven off the front of the cylinder head by one timing chain. The chain is driven by a sprocket that is located on the crankshaft. The piston assembly is an aluminum piston with a cast iron connecting rod. The oil pump is driven by the crankshaft via a dedicated chain that is driven by the same sprocket that drives the timing chain.

Lower Engine Block

Item Part Number Description
1 6010 Cylinder block
2 6K318 Crankshaft rear oil seal and retainer
3 6477 Flywheel
4 6675 Oil pan
5 6714 Oil filter
6 Oil filter adapter
7 9278 Oil pressure sensor
8 6A785 Positive crankcase ventilation (PCV) valve
9 8575 Thermostat assembly
10 6622 Oil pump screen and pickup tube
11 Balancer assembly
Front Engine Block

Item Part Number Description
1 6C348 Drive belt pulley idler (without A/C)
2 8620 Accessory drive belt (without A/C)
3 19D629 A/C compressor
4 8620 Accessory drive belt (with A/C)
5 6316 Crankshaft damper
6 6C315 Crankshaft position sensor
7 6A340 Crankshaft pulley bolt
8 10300 Generator
9 3A674 Power steering pump
10 8501 Coolant pump
11 19A216 Drive belt pulley idler (with A/C)
12 6B209 Drive belt tensioner
13 6019 Engine front cover
14 6306 Crankshaft sprocket
15 6K254 Timing chain tensioner
16 6K255 Timing chain tensioner arm
17 6268 Timing chain
18 6K297 Timing chain guide
19 6A895 Oil pump chain
20 6C271 Oil pump chain tensioner
21 6659 Oil pump-to-cylinder block gasket
22 8597 Coolant bypass tube
23 6600 Oil pump
24 6M256 Oil pump chain guide
25 6652 Oil pump drive gear
26 6010 Cylinder block
Cylinder Head

Item Part Number Description
1 12A366 Coil-on-plug assembly
2 6M293 Valve cover
3 12K073 Camshaft position (CMP) sensor
4 6766 Oil filler cap
5 6M293 Valve cover gasket
6 Camshaft bearing caps
7 6A272 Camshaft (exhaust)
8 6A271 Camshaft (intake)
9 6500 Valve tappet (16 req'd)
10 6518 Valve spring retainer key (16 req'd)
11 6514 Valve spring retainer (16 req'd)
12 6513 Valve spring (16 req'd)
13 6A517 Valve stem seal (16 req'd)
14 6G004 Cylinder head temperature (CHT) sensor
15 12405 Spark plug (4 req'd)
16 6065 Cylinder head bolt (10 req'd)
17 6049 Cylinder head
18 6505 Exhaust valve (8 req'd)
19 6507 Intake valve (8 req'd)
20 6051 Head gasket
21 6010 Cylinder block
22 6C251 Camshaft sprocket (2 req'd)
23 Exhaust manifold gasket
24   Exhaust manifold
25 17K004 Engine lifting eye
Intake Manifold

Item Part Number Description
1 High pressure fuel tube (supply)
2 Coolant outlet adapter assembly
3 9D475 Exhaust gas recirculation (EGR) valve
4 9E926 Throttle body assembly
5 6051 Cylinder head gasket
6 6010 Cylinder block
7 12A699 Knock sensor
8 6754 Oil level indicator and tube assembly
9 9F715 Idle air control (IAC) valve assembly
10 9424 Intake manifold
11 9J559 Engine air shutoff control assembly
12 Intake manifold gasket
13 Coolant hose
14 6049 Cylinder head
15 9F593 Fuel injector (4 req'd)
16 9H487 Fuel injection supply manifold