Symptoms
|
Suspected 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 buildup on the valve stem)
|
Repair or replace as required.
|
Excessive worn or miss-aligned timing chain
|
Replace the timing chain and sprocket as required.
|
Worn camshaft lobes
|
Replace the camshaft.
|
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 oil of the correct viscosity.
|
|
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 camshaft 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.
|
|
Loose, damaged or blocked oil pump screen
|
| • |
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 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 connecting rods.
|
|
Broken crankshaft
|
|
Repair procedures
Special service tools