ME(H6DO)-21
Compression
MECHANICAL
2. Compression
A: INSPECTION
CAUTION:
After warming-up, engine becomes very hot. Be
careful not to burn yourself during measure-
ment.
1) After warming-up the engine, turn the ignition
switch to OFF.
2) Make sure that the battery is fully charged.
3) Release the fuel pressure.
PRESSURE, PROCEDURE, Fuel.>
4) Remove all the spark plugs.
4, REMOVAL, Spark Plug.>
5) Check the starter motor for satisfactory perfor-
mance and operation.
6) Hold the compression gauge tightly against the
spark plug hole.
NOTE:
When using a screw-in type compression gauge,
the screw (put into cylinder head spark plug hole)
should be less than 18 mm (0.71 in) long.
7) Fully open the throttle valve.
8) Crank the engine by means of the starter motor,
and read the maximum value on the gauge when
the pointer is steady.
9) Perform at least two measurements per cylinder,
and make sure that the values are correct.
Compression (350 rpm and fully open throttle):
Standard:
1,275 — 1,471 kPa (13.0 — 1.50 kgf/cm2,
185 — 213 psi)
Service limit:
1,128 kPa (11.5 kgf/cm2, 164 psi)
ME-00446
ME(H6DO)-86
Engine Trouble in General
MECHANICAL
3. Low output, hesitation and
poor acceleration
Engine control system A
Intake system Loosened or cracked intake duct A
Loosened or cracked PCV hose A
Loosened or cracked vacuum hose B
Defective intake manifold gasket B
Defective throttle body gasket B
Defective PCV valve B
Loosened oil filler cap B
Dirty air cleaner element A
Fuel line Defective fuel pump and relay B
Clogged fuel line B
Lack of or insufficient fuel C
Chain Defective timing B
Compression Incorrect valve clearance B
Loosened spark plug or defective gasket B
Loosened cylinder head bolt or defective gasket B
Improper valve sealing B
Defective valve stem C
Wor n or broken valve spr ing B
Wor n or stuck piston r ings, cylinder and piston C
Incorrect valve timing A
Improper engine oil (low viscosity) B
Tr o u b l e o f t a p p e t C
Tr o u b l e o f t a p p e t . I n c a s e n o i s e o c c u r s w i t h v a l v e m o v -
ing. Or the harness involved to oil switching solenoid
valve, variable valve lift diagnosis oil pressure switch
and variable valve lift has trouble in a past.
B
Lubrication system Incorrect oil pressure B
Cooling system Over-heating C
Over-cooling C
Others Evaporative emission control system malfunction A
Symptom Problem parts etc. Possible cause RANK
ME(H6DO)-90
Engine Noise
MECHANICAL
29.Engine Noise
A: INSPECTION
(NOTE*)
When disconnecting the fuel injector connector, the malfunction indicator light illuminates and DTC is stored in ECM memory.
Therefore, carry out the clear memory mode and inspection
mode after connecting the fuel injector connector.
Ty p e o f s o u n d C o n d i t i o n P o s s i b l e c a u s e
Regular clicking soundSound increases as engine
speed increases.
•Valve mechanism is defective.
•Incorrect valve clearance
•Worn valve rocker
•Worn camshaft
•Broken valve spring
•Trouble of tappet
Heavy and dull clankOil pressure is low.•Worn camshaft main bearing
•Worn connecting rod bearing (large end)
Oil pressure is normal. Damaged engine mounting
High-pitched clank
Sound is noticeable when
accelerating with an overload
condition.
•Ignition timing advanced
•Accumulation of carbon inside combustion chamber
•Wrong spark plug
•Improper gasoline
Clank when engine speed is
between 1,000 and 2,000
rpms.
Sound is reduced when fuel
injector connector of noisy cyl-
inder is disconnected.
(NOTE*)
•Worn crankshaft main bearing
•Worn bearing at crankshaft end of connecting rod
Knocking sound when engine
is operating under idling speed
and engine is warm
Sound is reduced when fuel
injector connector of noisy cyl-
inder is disconnected.
(NOTE*)
•Worn cylinder liner and piston ring
•Broken or stuck piston ring
•Worn piston pin and hole at piston end of connecting rod
Sound is not reduced if each
fuel injector connector is dis-
connected in turn. (NOTE*)
•Unusually worn valve lifter
•Worn cam gear
•Worn camshaft journal bore in crankcase
Squeaky sound — • Insufficient generator lubrication
Rubbing sound — • Poor contact of generator brush and rotor
Gear scream when starting
engine—•Defective ignition starter switch
•Worn gear and starter pinion
Sound like polishing glass with
a dry cloth—•Loose drive belt
•Defective water pump shaft
Hissing sound —•Insufficient compression
•Air leakage in air intake system, hose, connection or manifold
Timing belt noise —•Loose timing belt
•Belt contacting with case/adjacent part
Va l ve t a p p e t n o i s e —•Incorrect valve clearance
•Trouble of tappet
