Contaminated Lube oil
| Cause | Correction | |
| Coolant in the oil, internal engine component leaks |
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Refer to Troubleshooting Logic for coolant loss. |
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| Excessive oil sludge |
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Review oil and filter change intervals. |
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Make sure the correct oil is being used. |
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| Fuel in the oil, engine operating too cold |
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Review the operation for excessive idling resulting in the engine running below normal temperature. |
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| Fuel pump seal leaking |
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Replace the pump. |
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| Injector needle valves not sealing |
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Locate and replace malfunctioning injector. |