Hyundai Accent: Repair procedures
Compession Pressure Inspection
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If the there is lack of power, excessive oil consumption
or poor fuel economy, measure the compression pressure.
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1. |
Make sure the oil in the crankcase is of the correct
viscosity and at the correct level and that the battery is correctly
charged. Operate the vehicle until the engine is at normal operating
temperature. Turn the ignition switch to the OFF position.
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2. |
Remove the engine cover.
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3. |
Disconnect the injector extension connector (A) and
the ignition coil connectors (B).
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4. |
Remove the ignition coils (A).
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5. |
Remove the spark plugs.
Using a 16mm plug wrench, remove the 4 spark plugs.
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6. |
Check the cylinder compression pressure.
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(1) |
Insert a compression gauge into the spark
plug hole.
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(2) |
Set the throttle plate in the wide-open position.
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(3) |
While cranking the engine, measure the compression
pressure.
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Always use a fully charged battery
to obtain engine speed of 250rpm or more.
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(4) |
Repeat step 1) through 3) for each cylinder.
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This measurement must be done in
as short time as possible.
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Compression
pressure
Standard : 1225.83kPa (12.5kg/cm²,
177.79psi) (200~250 rpm)
Minimum : 1078.73kPa (11.0kg/cm²,
156.46psi)
Difference between each cylinder
:
98kPa (1.0kg/cm², 14psi) or less
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(5) |
If the cylinder compression in one or more
cylinders is low, pour a small amount of engine oil into the
cylinder through the spark plug hole and repeat step 1) through
3) for cylinders with low compression.
| A. |
If adding oil helps the compression,
it is likely that the piston rings and/or cylinder bore
are worn or damaged.
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| B. |
If pressure stays low, a valve may
be sticking or seating is improper, or there may be
leakage past the gasket.
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7. |
Install the spark plugs.
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8. |
Install the ignition coil.
Tightening torque
:
9.8 ~ 11.8 N.m (1.0 ~ 1.2 kgf.m, 7.2 ~ 8.7
lb-ft)
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9. |
Connect the injector extension connector and the
ignition coil connectors.
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10. |
Install the engine cover.
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Valve Clearance Inspection And Adjustment
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Inspect and adjust the valve clearance when the engine
is cold (Engine coolant temperature : 20°C) and cylinder head is installed
on the cylinder block.
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1. |
Remove the cylinder head cover. (Refer to Timing
system)
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2. |
Set No.1 cylinder to TDC/compression.
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(1) |
Turn the crankshaft pulley and align its
groove with the timing mark of the timing chain cover.
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(2) |
Check that the marks of the intake and exhaust
CVVT sprockets are in straight line on the cylinder head surface
as shown in the illustration. If not, turn the crankshaft one
revolution (360°).
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3. |
Inspect the valve clearance.
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(1) |
Check only the intake valves of the 1st and
2nd cylinders and exhaust valves of the 1st and 3rd cylinders
for their clearance.
| A. |
Using a thickness gauge, measure
the clearance between the tappet and the base circle
of camshaft.
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| B. |
Record the out-of-specification valve
clearance measurements. They will be used later to determine
the required tappet for adjusting.
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Valve clearance specification (Engine
coolant temperature : 20°C [68°F])
Limit
Intake : 0.17 ~ 0.23mm (0.0067 ~
0.0091in.)
Exhaust : 0.22 ~ 0.28mm (0.0087 ~
0.0110in.)
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(2) |
Turn the crankshaft pulley one revolution
(clockwise 360°) and align its groove with timing mark of the
timing chain cover.
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(3) |
Check the intake valves of the 3rd and 4th
cylinders and exhaust valves of the 2nd and 4th cylinders for
their clearance.
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4. |
Adjust the intake and exhaust valve clearance.
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(1) |
Set the No.1 cylinder to the TDC/compression
position.
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(2) |
Remove the timing chain. (Refer to Timing
system)
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Put paint marks on the timing chain
links (2 places) that meet with the timing marks of
the intake and exhaust CVVT sprockets.
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(3) |
Remove the camshaft bearing caps (A) with
the order below.
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(4) |
Remove the intake camshaft assembly.
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(5) |
Remove the exhaust camshaft assembly.
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(6) |
Measure the thickness of the removed tappet
using a micrometer.
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(7) |
Calculate the thickness of a new tappet so
that the valve clearance comes within the specificified value.
Valve clearance (Engine coolant temperature
: 20°C)
T : Thickness of removed tappet
A : Measured valve clearance
N : Thickness of new tappet
Intake : N = T + [A - 0.20mm(0.0079in.)]
Exhaust : N = T + [A - 0.25mm (0.0098in.)]
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(8) |
Select a new tappet with a thickness as close
as possible to the caculated value.
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Shims are available in 41 size increments
of 0.015mm (0.0006in.) from 3.00mm (0.118in.) to 3.690mm
(0.1417in.)
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(9) |
Place a new tappet on the cylinder head.
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(10) |
Install the exhaust camshaft assembly.
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(11) |
Install the intake camshaft assembly.
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(12) |
Install the camshaft bearing caps with the
order below.
Tightening
torque :
1st step
M6 bolt :
5.9 N.m (0.6 kgf.m, 4.3 lb-ft)
M8 bolt :
9.8 N.m (1.0 kgf.m, 7.2 lb-ft)
2nd step
M6 bolts :
11.8 ~ 12.7N.m (1.2 ~ 1.3kgf.m, 8.7
~ 9.4lb-ft)
M8 bolts :
18.6 ~ 22.6N.m (1.9 ~ 2.3kgf.m, 13.7
~ 16.6lb-ft)
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(13) |
Install the timing chain. (Refer to Timing
system)
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(14) |
Turn the crankshaft two turns in the operating
direction(clockwise) and check that the marks of the intake
and exhaust CVVT sprockets are in straight line on the cylinder
head surface.
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(15) |
Recheck the valve clearance.
Valve clearance (Engine coolant temperature
: 20°C)
[Specification]
Intake : 0.17 ~ 0.23mm (0.0067 ~
0.0091in.)
Exhaust : 0.22 ~ 0.28mm (0.0087 ~
0.0110in.)
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Description
Specifications
Limit
General
Type
In-line, DOHC
Number of cylinders
...
Troubleshooting
Symptom
Suspect area
Remedy
Engine misfire with abnormal internal lower engine noises.
Loose or improperly installed e ...
Specifications
Troubleshooting