ENGINE DIAGNOSIS
| SYMPTOMS | PROBABLE CAUSE | REMEDY |
|---|---|---|
| Compression is too low | Blown cylinder head gasket | Replace the gasket. |
| Worn or damaged piston rings | Replace the rings. | |
| Worn piston or cylinder | Repair or replace the piston and/or the cylinder block. | |
| Worn or damaged valve seat | Repair or replace the valve and/or the seat ring | |
| Drop in engine oil pressure | Engine oil level is too low | Check the engine oil level. |
| Malfunction of engine oil pressure switch | Replace the engine oil pressure switch. | |
| Clogged oil filter | Install a new filter. | |
| Worn oil pump gears or cover | Replace the gears and/or the cover. | |
| Thin or diluted engine oil | Change the engine oil to the correct viscosity. | |
| Stuck (opened) oil relief valve | Repair the relief valve. | |
| Excessive bearing clearance | Replace the bearings. | |
| Engine oil pressure too high | Stuck (closed) oil relief valve | Repair the relief valve. |
| Noisy valves | Incorrect valve clearance | Adjust valve clearance |
| Thin or diluted engine oil (low engine oil pressure) | Change the engine oil. | |
| Worn or damaged valve stem or valve guide | Replace the valve and/or the guide. | |
| Connecting rod noise/main bearing noise | Insufficient oil supply | Check the engine oil level. |
| Thin or diluted engine oil | Change the engine oil. | |
| Excessive bearing clearance | Replace the bearings. |
SYMPTOM CHART
INSPECTION
- Check the engine oil pan for cracks.
- Check the engine oil pan sealant-coated surface for damage and deformation.
Scheme 1
Required Special Tools
- MB991883: Flywheel Stopper
- MB991448: Bush Remover And Installer Base