| Symptom | Suspect area | Remedy | 
| Engine misfire with abnormal internal lower engine noises. | Loose or improperly installed drive plate. | Repair or replace the drive plate 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 can cause the valve not to close properly.) | 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 HLA. | 
| Engine misfire with coolant consumption. | |  •  | Faulty cylinder head gasket and/or cracking 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, valve 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) | Inspection 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. | Drain the oil. 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. | 
| Stretched 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 and valve lifters as required. | 
| Worn valve guides or valve stems. | Inspect the valves and valve guides, then repair 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 as required. | 
| Lower engine noise, regardless of engine speed. | Low oil pressure. | Repair or replace damaged components as required. | 
| Loose or damaged drive plate. | Repair or replace the drive plate. | 
| Damaged oil pan, contacting the oil pump screen. | Inspect the oil pan. 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 and cylinder bore. Repair as required. | 
| Excessive piston pin-to-bore 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 as required.
 |  •  | The connecting rod bearings.  |  
 
|  •  | The crankshaft journal.  |  
 
 | 
| Excessive crankshaft bearing clearance. | Inspect the following components and repair as required.
 |  •  | The crankshaft bearings.  |  
 
|  •  | The crankshaft journals.  |  
 
 | 
| Incorrect piston, piston pin and connecting rod installation. | Verify the piston pins and connecting rods are installed correctly. Repair as required. | 
| Engine noise under load. | Low oil pressure. | Repair or replace as required. | 
| Excessive connecting rod bearing clearance. | Inspect the following components and repair as required.
 |  •  | The connecting rod bearings.  |  
 
 | 
| Excessive crankshaft bearing clearance. | Inspect the following components and repair as required.
 |  •  | The crankshaft bearings.  |  
 
|  •  | The crankshaft journals.  |  
 
|  •  | The cylinder block crankshaft bearing bore.  |  
 
 | 
| Engine will not crank. (crankshaft will not rotate) | Hydraulically locked cylinder.
 |  •  | Coolant/antifreeze in cylinder.  |  
 
 | Remove spark plugs and check for fluid. Inspect for broken head gasket. Inspect for cracked engine block or cylinder head. Inspect for a sticking fuel injector and/or leaking fuel regulator. | 
| Broken timing chain and/or timing chain gears. | Inspect timing chain and gears. Repair as required. | 
Foreign material in cylinder. 
 | Inspect cylinder for damaged components and/or foreign materials. Repair or replace as required. | 
| Seized crankshaft or connecting rod bearings. | Inspect crankshaft and connecting rod bearing. Repair or replace as required. | 
| Bent or broken connecting rod. | Inspect connecting rods. Repair or replace as required. | 
| Broken crankshaft. | Inspect crankshaft. Repair or replace as required. |