| 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.
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| • |
Coolant consumption may or may not cause the engine to overheat.
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|
| • |
Inspect the cylinder head and engine block for damage to the coolant passages and/or a faulty head gasket.
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| • |
Repair or replace as required.
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| 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.
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| • |
Repair or replace as required.
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| Engine noise on start-up, but only lasting a few seconds. |
Incorrect oil viscosity |
| • |
Install the correct viscosity oil.
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| Worn crankshaft thrust bearing. |
| • |
Inspect the thrust bearing and crankshaft.
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| • |
Repair or replace as required.
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| 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.
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| • |
Replace the timing camshaft and valve lifters as required.
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|
| 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.
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| • |
Repair or replace as required.
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| Oil pump screen loose, damaged or restricted. |
| • |
Inspect the oil pump screen.
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| • |
Repair or replace as required.
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| Excessive piston-to-cylinder bore clearance. |
| • |
Inspect the piston, piston pin and cylinder bore.
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| • |
Repair or replace as required.
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| Excessive piston pin-to-piston clearance |
| • |
Inspect the piston, piston pin and the connecting rod.
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| • |
Repair or replace as required.
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| Excessive connecting rod bearing clearance |
Inspect the following components and repair or replace as required.
| • |
The connecting rod bearings.
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| • |
The crankshaft pin journals.
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| Excessive crankshaft bearing clearance |
Inspect the following components, and repair or replace as required.
| • |
The crankshaft bearings.
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| • |
The crankshaft main journals.
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| Incorrect piston, piston pin and connecting rod installation |
| • |
Verify the piston pins and connecting rods are installed correctly.
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| 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.
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|
| Excessive crankshaft bearing clearance |
Inspect the following components, and repair or replace as required.
| • |
The crankshaft bearings.
|
| • |
The crankshaft main journals.
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| Engine will not crank-crankshaft will not rotate |
Hydraulically locked cylinder
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Coolant/antifreeze in cylinder.
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|
| 1) |
Remove spark plugs and check for fluid.
|
| 2) |
Inspect for broken head gasket.
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| 3) |
Inspect for cracked engine block or cylinder head.
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| 4) |
Inspect for a sticking fuel injector and/or leaking fuel regulator.
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| Broken timing chain and/or timing chain and/or timing chain gears. |
| 1) |
Inspect timing chain and gears.
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| Material in cylinder
|
| 1) |
Inspect cylinder for damaged components and/or foreign materials.
|
| 2) |
Repair or replace as required.
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| Seized crankshaft or connecting rod bearings. |
| 1) |
Inspect crankshaft and connecting rod bearing.
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| Bent or broken connecting rod. |
| 1) |
Inspect connecing rods.
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| Broken crankshaft |
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