Symption
|
Suspect area
|
Remedy
|
Engine misfire with abnormal internal lower engine
noises.
|
Worn
crankshaft bearings Loose or improperly
engine filwheel
|
Replace the
crankshaft and bearings as required. Repair or replace the flywheel as
required.
|
Worn piston
rings (Oil consumption may or may not
cause the engine to misfire.)
|
Inspect the
cylinder for a loss of compression. Repair or replace as required.
|
Worn
crankshaft thrust bearings
|
Replace the
crankshaft and bearings as required
|
Engine misfire with abnormal valve train
noise.
|
Stuck
valves. (Carbon buidup on the valve
stem)
|
Repair or
replace as required
|
Excessive
worn or mis-aligned timing chain
|
Replace the
timing chain and sprocket as required.
|
Worn
camshaft lobes.
|
Replace the
camshaft and valve lifters.
|
Engine misfire
with coolant consumption
|
•
|
Faulty cylinder head gasket or other
damage to the cylinder head and engine block cooling
system. |
•
|
Coolant consumption may or may not cause
the engine to overheat. | |
•
|
Inspect the cylinder head and engine
block for damage to the coolant passages and/or a faulty head
gasket. |
•
|
Repair or replace as
required. | |
Engine misfire with excessive oil
consumption
|
Worn
valves, guides and/or valve stem oil seals.
|
Repair or
replace as required.
|
Worn piston
rings. (Oil consumption may or may not
cause the engine to misfire)
|
•
|
Inspect the cylinder for a loss of
compression. |
•
|
Repair or replace as
required. | |
Engine noise on start-up, but only lasting a few
seconds.
|
Incorrect oil
viscosity
|
•
|
Install the correct viscosity
oil. | |
Worn
crankshaft thrust bearing.
|
•
|
Inspect the thrust bearing and
crankshaft. |
•
|
Repair or replace as
required. | |
Upper engine noise, regardless of engine
speed.
|
Low oil
pressure
|
Repair or
replace as required.
|
Broken
valve spring.
|
Replace the
valve spring.
|
Worn or
dirty valve lifters.
|
Replace the
valve lifters.
|
Stetched or
broken timing chain and/or damaged sprocket teeth.
|
Replace the
timing chain and sprockets.
|
Worn timing
chain tensioner, if applicable.
|
Replace the
timing chain tensioner as required.
|
Worn camshaft
lobes.
|
•
|
Inspect the camshaft
lobes. |
•
|
Replace the timing camshaft and valve
lifters as required. | |
Worn valve
guides or valve stems.
|
Inspect the
valves and valve guides, then repair or replace as
required.
|
Stuck
valves. (Carbon on the valve stem or valve seat may cause the valve
to stay open.
|
Inspect the
valves and valve guides, then repair or replace as
required.
|
Worn drive
belt, idler, tensioner and bearing.
|
Replace as
required
|
Lower engine noise, regardless of engine
speed
|
Low oil
pressure
|
Repair or
required.
|
Loose or
damaged flywheel.
|
Repair or
replace the flywheel.
|
Damaged oil
pan, contacting the oil pump screen.
|
•
|
Inspect the oil pump
screen. |
•
|
Repair or replace as
required. | |
Oil pump
screen loose, damaged or restricted.
|
•
|
Inspect the oil pump
screen. |
•
|
Repair or replace as
required. | |
Excessive
piston-to-cylinder bore clearance.
|
•
|
Inspect the piston, piston pin and
cylinder bore. |
•
|
Repair or replace as
required. | |
Excessive
piston pin-to-piston clearance
|
•
|
Inspect the piston, piston pin and the
connecting rod. |
•
|
Repair or replace as
required. | |
Excessive
connecting rod bearing clearance
|
Inspect the
following components and repair or replace as required.
•
|
The connecting rod
bearings. |
•
|
The crankshaft pin
journals. | |
Excessive
crankshaft bearing clearance
|
Inspect the
following components, and repair or replace as required.
•
|
The crankshaft
bearings. |
•
|
The crankshaft main
journals. |
|
Incorrect
piston, piston pin and connecting rod installation
|
•
|
Verify the piston pins and connecting
rods are installed correctly. |
|
Engine noise under load
|
Low oil
pressure
|
Repair or
replace as required.
|
Excessive
connecting rod bearing clearance
|
Inspect the
following components and repair or replace as required :
•
|
The connecting rod
bearings. |
|
Excessive
crankshaft bearing clearance
|
Inspect the
following components, and repair or replace as required.
•
|
The crankshaft
bearings. |
•
|
The crankshaft main
journals. |
|
Engine will not crank-crankshaft will not
rotate
|
Hydraulically locked cylinder
•
|
Coolant/antifreeze in
cylinder. |
|
1. |
Remove spark plugs and check for
fluid. |
2. |
Inspect for broken head
gasket. |
3. |
Inspect for cracked engine block or
cylinder head. |
4. |
Inspect for a sticking fuel injector
and/or leaking fuel
regulator. | |
Broken timing
chain and/or timing chain and/or timing chain gears.
|
1. |
Inspect timing chain and
gears. |
|
Material in
cylinder
|
1. |
Inspect cylinder for damaged components
and/or foreign materials. |
2. |
Repair or replace as
required. | |
Seized
crankshaft or connecting rod bearings.
|
1. |
Inspect crankshaft and connecting rod
bearing. |
|
Bent or broken
connecting rod.
|
1. |
Inspect connecing
rods. |
|
Broken
crankshaft
|
|