Symption
|
Suspect area
|
Remedy
|
Engine misfire with abnormal internal lower engine noises.
|
Worn crankshaft bearings
Loose or out of specification engine flywheel
|
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
Out of specification valve clearances
|
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.
(Check and compare with known good vehicle to determine normal condition.)
|
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. |
|
Out of specification valve clearances
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
|
|
Kia Optima: Troubleshooting
Repair procedures
Special Service Tools