Symption
| Suspect area
| Remedy
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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.
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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.
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Worn crankshaft thrust bearings
| Replace the crankshaft and bearings as required
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Engine misfire with abnormal valve train noise.
| Stuck valves.
(Carbon buidup on the valve stem)
| Repair or replace as required
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Excessive worn or mis-aligned timing chain
Out of specification valve clearances
| Replace the timing chain and sprocket as required.
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Worn camshaft lobes.
| Replace the camshaft and valve lifters.
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Engine misfire with coolant consumption
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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.
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Worn piston rings.
(Oil consumption may or may not cause the engine to misfire)
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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.
(Check and compare with known good vehicle to determine normal condition.)
| Incorrect oil viscosity
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Install the correct viscosity oil. |
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Worn crankshaft thrust bearing.
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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.
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Broken valve spring.
| Replace the valve spring.
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Worn or dirty valve lifters.
| Replace the valve lifters.
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Stetched or broken timing chain and/or damaged sprocket teeth.
| Replace the timing chain and sprockets.
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Worn timing chain tensioner, if applicable.
| Replace the timing chain tensioner as required.
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Worn camshaft lobes.
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Inspect the camshaft lobes. |
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Replace the timing camshaft and valve lifters as required. |
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Out of specification valve clearances
Worn valve guides or valve stems.
| Inspect the valves and valve guides, then repair or replace as required.
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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.
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Worn drive belt, idler, tensioner and bearing.
| Replace as required
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Lower engine noise, regardless of engine speed
| Low oil pressure
| Repair or replace as required
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Loose or damaged flywheel.
| Repair or replace the flywheel.
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Damaged oil pan, contacting the oil pump screen.
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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.
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Inspect the oil pump screen. |
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Repair or replace as required. |
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Excessive piston-to-cylinder bore clearance.
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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
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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.
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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.
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The crankshaft bearings. |
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The crankshaft main journals. |
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Incorrect piston, piston pin and connecting rod installation
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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.
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Excessive connecting rod bearing clearance
| Inspect the following components and repair or replace as required :
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The connecting rod bearings. |
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Excessive crankshaft bearing clearance
| Inspect the following components, and repair or replace as required.
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The crankshaft bearings. |
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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. |
| 3) |
Inspect for cracked engine block or cylinder head. |
| 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.
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| 1) |
Inspect timing chain and gears. |
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Material in cylinder
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| 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.
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| 1) |
Inspect crankshaft and connecting rod bearing. |
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Bent or broken connecting rod.
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| 1) |
Inspect connecting rods. |
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Broken crankshaft
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