6-8 ENGINE DIAGNOSIS (C24SE)
Condition Possible cause Correction
Engine overheating Level of Engine Coolant too low Replenish
Thermo switch or fan motor
defective Replace
Thermostat defective Replace
Engine Coolant pump defective Correct or replace
Radiator clogged Clean or replace
Radiator filter cap defective Replace
Level of oil in engine crankcase
too low or wrong oil in engine Change or replenish
Resistance in exhaust system
increased Clean exhaust system or replace
defective parts
Throttle Position Sensor
adjustment incorrect Adjust Wide Open Throttle switch
setting
Throttle Position Sensor circuit
open or shorted Correct or replace
Cylinder head gasket damaged Replace
Cooling Fan clutch defective Replace
Fan belt slipping Adjust tension of V-belt or replace
V-belt
Engine overcooling Thermostat defective Replace (Use a thermostat set to
open at 92C (197.6F))
Engine lacks compression - Refer to Hard Start
Others Tire inflation pressure abnormal Adjust to recommend pressures
Brake drag Adjust
Clutch slipping Adjust or replace
Level of oil in engine crankcase
too high Correct level of engine oil
Engine Noisy
Abnormal engine noise often consists of various
noises originating in rotating parts, sliding parts and
other moving parts of the engine. It is, therefore,
advisable to locate the source of noise systematically.
Condition Possible cause Correction
Noise from crank journals or from
crank bearings
(Faulty crank journals and crank
bearings usually make dull noise
that becomes more evident when
accelerating) Oil clearance increased due to
worn crank journals or crank
bearings Replace crank bearings and
crankshaft or regrind crankshaft
and install the over size bearing
Crankshaft out of round Replace crank bearings and
crankshaft or regrind crankshaft
and install the over size bearing
Crank bearing seized Replace crank bearings and
crankshaft or regrind crankshaft
and install the over size bearing
6-12 ENGINE DIAGNOSIS (C24SE)
Engine Oil Consumption Excessive
Condition Possible cause Correction
Oil leaking Oil pan drain plug loose Retighten or replace gasket
Oil pan setting bolds loosened Retighten
Oil pan gasket broken Replace gasket
Front cover retaining bolts loose
or gasket broken Retighten or replace gasket
Head cover retaining bolts loose
or gasket broken Retighten or replace gasket
Oil filter adapter cracked Replace
Oil filter attaching bolt loose or
rubber gasket broken Retighten or replace oil filter
Crankshaft front or rear oil seal
defective Replace oil seal
Oil pressure unit loose or broken Retighten or replace
Blow-by gas hose broken Replace hose
Engine/Transmission coupling
area Replace oil seal
Oil leaking into combustion
chambers due to poor seal in
valve system Valve stem oil seal defective Replace
Valve stem or valve guide worn Replace valve and valve guide
Oil leaking into combustion
chambers due to poor seal in
cylinder parts Cylinders and pistons worn
excessively Rebore cylinder and replace
pistons and others
Piston ring gaps incorrectly
positioned Correct
Piston rings set with wrong side
up Correct
Piston rings sticking Rebore cylinder and replace
pistons and others
Piston ring and ring groove worn Replace pistons and others
Return ports in oil rings clogged Clean piston and replace rings
Crank case ventilation, Positive
Crankcase Ventilation System
malfunctioning Positive Crankcase Ventilation
Hose clogged Clean
Others Improper oil viscosity Use oil of recommended S.A.E.
viscosity
Continuous high speed driving
and or severe usage such as
trailer towing Continuous high speed operation
and or severe usage will normally
cause increased oil consumption
ENGINE DIAGNOSIS (C24SE) 6-13
Fuel Consumption Excessive
Condition Possible cause Correction
Trouble in fuel system Mixture too rich or too lean due to
trouble in fuel injection system Refer to "Abnormal Combustion"
Fuel cut function does not act Refer to "Abnormal Combustion"
Trouble in ignition system Misfiring or abnormal combustion
due to trouble in ignition system Refer to Hard Start or Abnormal
Combustion Troubleshooting
Guide
Others Engine idle speed too high Reset Idle Air Control Valve
Returning of accelerator control
sluggish Correct
Fuel system leakage Correct or replace
Clutch slipping Correct
Brake drag Correct
Selection of transmission gear
incorrect Caution operator of incorrect gear
selection
Oil Problems
Condition Possible cause Correction
Oil pressure too low Wrong oil in use Replace with correct engine oil
Relief valve sticking Replace
Oil pump not operating properly Correct or replace
Oil pump strainer clogged Clean or replace strainer
Oil pump worn Replace
Oil pressure gauge defective Correct or replace
Crankshaft bearing or connecting
rod bearing worn Replace
Oil contamination Wrong oil in use Replace with new engine oil
Oil filter clogged Replace oil filter
Cylinder head gasket damage Replace gasket
Burned gases leaking Replace piston and piston rings or
rebore cylinders
Oil not reaching valve system Oil passage in cylinder head or
cylinder body clogged Clean or correct
Engine Oil Pressure Check
1. Check for dirt, gasoline or water in the engine
oil.
a. Check the viscosity of the oil.
b. Change the oil if the viscosity is outside the
specified standard.
c. Refer to the "Maintenance and Lubrication"
section of this manual.
2. Check the engine oil level.
The level should fall somewhere between the
"ADD" and the "FULL" marks on the oil level
dipstick.
If the oil level does not reach the "ADD" mark on
the oil level dipstick, engine oil must be added. 3. Remove the oil pressure unit.
4. Install an oil pressure gauge.
5. Start the engine and allow the engine to reach
normal operating temperature (About 80C).
6. Measure the oil pressure.
Oil pressure should be:
150 kPa(21.8 psi) at idle speed.
7. Stop the engine.
8. Remove the oil pressure gauge
9. Install the oil pressure unit.
10. Start the engine and check for leaks.
6A-2 ENGINE MECHANICAL (C24SE)
PAGE
Camshaft Housing, Check for Plance Surface ......................................................... 6A-39
Cylinder Head, Removal and Installation .................................................................. 6A-39
Cylinder Head, Disassemble and Assemble ............................................................. 6A-42
Valve, Grind ................................................................................................................. 6A-44
Valve Guide, Ream ..................................................................................................... 6A-44
Valve Seating, Mill ....................................................................................................... 6A-45
Cylinder Head, Overhaul............................................................................................. 6A-45
Flywheel ....................................................................................................................... 6A-46
Starter Ring Gear(Manual Transmission) ................................................................. 6A-47
Seal Ring, Crankshaft ................................................................................................. 6A-48
Seal Ring, Crankshaft Rear ........................................................................................ 6A-48
Oil Pan and Bearing Bridge........................................................................................ 6A-49
OPERATIONS ON CRANK DRIVE ................................................................................... 6A-51
Con-Rod Bearing......................................................................................................... 6A-51
Piston with Con-Rod ................................................................................................... 6A-51
Con-Rod ....................................................................................................................... 6A-52
Pistion Rings ............................................................................................................... 6A-53
OPERATIONS ON REMOVED ENGINE ........................................................................... 6A-55
Crankshaft ................................................................................................................... 6A-55
Bearing Free Play Measurement ................................................................................ 6A-57
Plastigage Method ...................................................................................................... 6A-57
Micrometer and gauge method .................................................................................. 6A-58
Bypass Valve ............................................................................................................... 6A-59
Oil Filter ....................................................................................................................... 6A-59
Oil Pump ...................................................................................................................... 6A-59
Oil Pump Safety Valve ................................................................................................ 6A-60
Oil Pump(Overhaul) .................................................................................................... 6A-60
OPERATIONS ON OIL CIRCULATION ............................................................................ 6A-61
Cylinder Head Safety Valve ........................................................................................ 6A-61
OPERATIONS ON COOLING SYSYTEM ......................................................................... 6A-63
Cooling System, Check for Leakes ........................................................................... 6A-63
Cooling System, Fill Up and Bleed ............................................................................ 6A-63
Refill Coolant ............................................................................................................... 6A-64
Ignition Timing, Check................................................................................................ 6A-64
ENGINE MECHANICAL (C24SE) 6A-3
PAGE
ENGINE EXTERNAL PARTS ............................................................................................ 6A-65
Radiator ....................................................................................................................... 6A-65
Thermostat................................................................................................................... 6A-66
Water Pump ................................................................................................................. 6A-66
Coating sealing surfaces with Silicone Grease ....................................................... 6A-67
Alternator ..................................................................................................................... 6A-67
Starter .......................................................................................................................... 6A-67
V-belt Tension of Alternator ....................................................................................... 6A-68
FUEL INJECTION SYSTEM.............................................................................................. 6A-69
Map Sensor.................................................................................................................. 6A-69
Pressure Regulator ..................................................................................................... 6A-69
ECM (Engine Control Module).................................................................................... 6A-69
ECT ............................................................................................................................... 6A-70
Idle Air Control(IAC) Valve.......................................................................................... 6A-70
Ignition Coil ................................................................................................................. 6A-70
Crank Position Sensor................................................................................................ 6A-71
FUEL INJECTOR .............................................................................................................. 6A-72
Knock Sensor .............................................................................................................. 6A-72
Oxygen Sensor ............................................................................................................ 6A-73
Throttle Valve Position Sensor .................................................................................. 6A-73
Acclelerator Pedal and Cable..................................................................................... 6A-73
Air Cleaner Filter ......................................................................................................... 6A-74
Spark Plug Thread ...................................................................................................... 6A-75
TECHNICAL DATA ........................................................................................................... 6A-76
Recommended Troque Values................................................................................... 6A-87
SPECIAL SERVICE TOOL................................................................................................ 6A-88
ENGINE MECHANICAL (C24SE) 6A-11
Main Data and Specifications
Engine - General C24SE
Engine type Four-cycle, water cooled cross-flow with single over head
camshaft
Micro-computer control, fuel injection
Combustion chamber type (Volume) Hemispherical (43.3cm3)
Timing train system Belt drive
No. of cylinders-bore stroke mm (in) 4-87.5100.0 (3.443.93)
Bore Spacing(C/L to C/L) 93.0 mm (3.66 in)
Firing Order 1-3-4-2
BoreStroke mm (in) 87.5100.0 (3.443.93)
Total piston displacement cm3 (in3) 2,405(146.80)
Combustion Chamber Volume 43.3cm3
No. of piston ring Compression ring: 2, Oil ring: 1
Compression pressure kg/cm2 (psi/pa) 12.2-16.3 (174-232/1200-1600)
Ignition timing (BTDC) No adjustment
Idling speed: rpm(WO/AC,W/AC) A/C off 825
Valve clearances (At cold)
Intake mm (in) 0 (0) (Hydraulic valve lash adjustment)
Exhaust mm (in) 0 (0) ( " )
Open at (BTDC) deg 1730’
Close at (ABDC) deg 7630’
Exhaust valves
Open at (BBDC) deg 5830’
Close at (ATDC) deg 3530’
Ignition system Fully transistorized battery ignition
Distributor type Not applicable, Electronic Spark Timing control
Distributor advance type Not applicable, Electronic Spark Timing control
Spark plug type RN9YC4
Spark plug gap mm (in) 1.0--1.1 (0.039--0.043)
Lubrication system
Lubricating method Fully flow pressure circulation
Special engine oil (API grade) SE, SF, SG or SH grade
Oil pressure kg/cm2 (psi/Pa) rpm 4-4.6 (56.9-65.4/400-450)
Oil pump type Gear
Oil filter type Cartridge full flow
Oil capacity lit. (US/UK gal.) 4.25
Cooling system
Radiator type Corrugated fin with reserve tank
Coolant capacity lit.
(US/UK gal.) 2.3 (0.66/0.55)
Water pump type Centrifugal
Thermostat Wax pellet with jiggle hole
ENGINE MECHANICAL (C24SE) 6A-13
Valve System C24SE
Actuation Type Direct-acting Inverted Bucked Tappet
Valve Clearance Adjustment Hydraulic
Valve Rotor Type None
Inlet-Valve Material Chromium Alloyed Steel
-Seat Insert Material Sintered Iron
Exhaust-Valve Material Head: Cr-Mn-Ni Alloyed Shaft: Cr-Si Alloyed &Cr plated
-Seat Insert Material Sintered Iron
Valve Spring Material GME 06 100-C1
Valve Guide Material QS 13 MR 00
Valve Seal Type Lip
Water Pump C24SE
Type Centrifugal
Drive-Material &Type HNBR Toothed-belt
Bearing Type Double Row Ball
Shaft Seal Type Mechanical Ceramic
Thermostat-Coolant C24SE
Type Bypass
Oil Pump & Filter C24SE
Type Gear Pump
Location Front of Engine
Drive Direct Crankshaft Driven
Filter Type Full Flow with Bypass for blocked filter
Oil & Oil Reservoir C24SE
Reservoir-Description & Location 1-piece below Engine
Reservoir Material Aluminum Alloy (pressure cast)
Replacement Oil Fill Volume
-With Filter change 4.25liters
-Without Filter change 4.00liters
Recommended Oil-Run-in 10W/30SG
-Service (above-18C) 10W/40SG
-Service (below-18C) 5W/30SG
Oil Classification API&CCMC
Ignition Components C24SE
Spark Plugs Conventional
Type Electronic Spark Control
No. of Coils &Type 2 Solid State
Coil Location Engine-mounted
Ignition Lead Type Inductive (hi-resistance)
ENGINE MECHANICAL (C24SE) 6A-59
Bypass Valve
Removal
1. Remove oil filter.
2. Remove bypass valve by cutting thread in locking disc
with M 10 tap (3rd stage), turning in M 10 bolt and taking
out bypass valve from seating.
Installation
1. Install bypass valve using drift (diameter approx.
15mm/0.6in.).
Oil Filter
Removal
1. Remove oil filter using commercially available tool.
Installation
1. Install oil filter by hand and oil seal ring.
2. Fill up engine oil while preventing overflow.
Oil Pump
Removal
1. Remove rear toothed belt cover, and oil pan according to
the corresponding operations.
2. Remove oil filter, wiring plug from oil pressure switch, oil
pump from cylinder block, and oil pressure switch from
oil pump.
Clean
Sealing surfaces
Installation
1. Install oil pressure switch to oil pump, oil pump to cylinder
block, oil pan, bearing bridge wiring plug, oil filter and
toothed belt cover.
Tighten (Torque)
Oil pressure switch to oil pump - 30 N
m (3.2 kgf
m)
Oil pump to cylinder block - 6 N
m (0.6 kgf
m)
Oil intake pipe to oil pump - 8 N
m (0.8 kgf
m)
Intake pipe bracket to cylinder block - 8 N
m (0.8 kgf
m)
*Insert bolts with Locktite (Refer to General Description
Recommended Liguid Gasket)