Page 1947 of 2453
ME(H6DO)-81
Connecting Rod
MECHANICAL
26.Connecting Rod
A: SPECIFICATION
Refer to “Cylinder Block” for removal and installa-
tion procedures of connecting rod.
Block.>
Cylinder Block.>
Page 1948 of 2453
ME(H6DO)-82
Crankshaft
MECHANICAL
27.Crankshaft
A: SPECIFICATION
Refer to “Cylinder Block” for removal and installa-
tion procedures of crankshaft.
62, REMOVAL, Cylinder Block.>
ME(H6DO)-64, INSTALLATION, Cylinder Block.>
Page 1949 of 2453

ME(H6DO)-83
Engine Trouble in General
MECHANICAL
28.Engine Trouble in General
A: INSPECTION
NOTE:
The “RANK” shown in the chart shows the possibilities of the cause of trouble in order from “most likely” to
“rarely”.
A — Most likely
B — Sometimes
C — Rarely
Symptom Problem parts etc. Possible cause RANK
1. Engine does not start.
1) Starter does not turn. Starter Defective battery-to-starter harness B
Defective starter switch C
Defective inhibitor switch or neutral switch C
Defective starter B
Battery Improper connection of terminal A
Run-down battery A
Defective charging system B
Fr iction Seizure of crankshaft and connecting rod bear ing C
Seized camshaft C
Seized or stuck piston and cylinder C
2) Initial combustion does
not occur.
Starter Defective starter C
Engine control system A
Fuel line Defective fuel pump and relay A
Lack of or insufficient fuel B
Chain Trouble B
Defective timing B
Compression Incorrect valve clearance C
Loosened spark plug or defective gasket C
Loosened cylinder head bolt or defective gasket C
Improper valve sealing C
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 B
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
Page 1950 of 2453

ME(H6DO)-84
Engine Trouble in General
MECHANICAL
3) Initial combustion occurs. Engine control system A
Intake system Defective intake manifold gasket B
Defective throttle body gasket B
Fuel line Defective fuel pump and relay C
Clogged fuel line C
Lack of or insufficient fuel B
Chain Trouble B
Defective timing B
Compression Incorrect valve clearance C
Loosened spark plug or defective gasket C
Loosened cylinder head bolt or defective gasket C
Improper valve sealing C
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 B
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
4) Engine stalls after initial
combustion.
Engine control system A
Intake system Loosened or cracked intake duct B
Loosened or cracked PCV hose C
Loosened or cracked vacuum hose C
Defective intake manifold gasket B
Defective throttle body gasket B
Dirty air cleaner element C
Fuel line Clogged fuel line C
Lack of or insufficient fuel B
Chain Trouble B
Defective timing B
Compression Incorrect valve clearance C
Loosened spark plug or defective gasket C
Loosened cylinder head bolt or defective gasket C
Improper valve sealing C
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 B
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
Symptom Problem parts etc. Possible cause RANK
Page 1951 of 2453

ME(H6DO)-85
Engine Trouble in General
MECHANICAL
2. Rough idle and engine
stall
Engine control system A
Intake system Loosened or cracked intake duct A
Loosened or cracked PCV hose A
Loosened or cracked vacuum hose A
Defective intake manifold gasket B
Defective throttle body gasket B
Defective PCV valve C
Loosened oil filler cap B
Dirty air cleaner element C
Fuel line Defective fuel pump and relay C
Clogged fuel line C
Lack of or insufficient fuel B
Chain Defective timing C
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 B
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
Defective rocker cover gasket C
Cooling system Over-heating C
Others Evaporative emission control system malfunction A
Stuck or damaged throttle valve B
Symptom Problem parts etc. Possible cause RANK
Page 1952 of 2453

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
Page 1953 of 2453

ME(H6DO)-87
Engine Trouble in General
MECHANICAL
4. Surging Engine control system A
Intake system Loosened or cracked intake duct A
Loosened or cracked PCV hose A
Loosened or cracked vacuum hose A
Defective intake manifold gasket B
Defective throttle body gasket B
Defective PCV valve B
Loosened oil filler cap B
Dirty air cleaner element B
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 C
Loosened cylinder head bolt or defective gasket C
Improper valve sealing C
Defective valve stem C
Wor n or broken valve spr ing C
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
Cooling system Over-heating B
Others Evaporative emission control system malfunction C
5. Engine does not return to
idle.
Engine control system A
Intake system Loosened or cracked vacuum hose A
Others Stuck or damaged throttle valve A
6. Dieseling (Run-on) Engine control system A
Cooling system Over-heating B
Others Evaporative emission control system malfunction B
Symptom Problem parts etc. Possible cause RANK
Page 1954 of 2453

ME(H6DO)-88
Engine Trouble in General
MECHANICAL
7. After burning in exhaust
system
Engine control system A
Intake system Loosened or cracked intake duct C
Loosened or cracked PCV hose C
Loosened or cracked vacuum hose B
Defective PCV valve B
Loosened oil filler cap C
Chain Defective timing B
Compression Incorrect valve clearance B
Loosened spark plug or defective gasket C
Loosened cylinder head bolt or defective gasket C
Improper valve sealing B
Defective valve stem C
Wor n or broken valve spr ing C
Wor n or stuck piston r ings, cylinder and piston C
Incorrect valve timing A
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 C
Cooling system Over-cooling C
Others Evaporative emission control system malfunction C
8. Knocking Engine control system A
Intake system Loosened oil filler cap B
Chain Defective timing B
Compression Incorrect valve clearance C
Incorrect valve timing 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
Cooling system Over-heating A
9. Excessive engine oil con-
sumption
Intake system Loosened or cracked PCV hose A
Defective PCV valve B
Loosened oil filler cap C
Compression Defective valve stem A
Wor n or stuck piston r ings, cylinder and piston A
Lubrication system Loosened oil pump attaching bolts and defective gas-
ket
B
Defective oil filter o-ring B
Defective crankshaft oil seal B
Defective rocker cover gasket B
Loosened oil drain plug or defective gasket B
Loosened oil pan fitting bolts or defective oil pan B
Symptom Problem parts etc. Possible cause RANK