Lube oil loss
| Cause | Correction | |
| External leaks |
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Visually inspect for oil leaks. |
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| Crankcase being overfilled |
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Verify that the dipstick is correctly marked. |
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| Incorrect oil (specification or viscosity) |
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Make sure the correct oil is being used. |
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Look fir reduced viscosity from dilution with fuel. |
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| Review/reduce the oil change intervals. |
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| Oil cooler leak |
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Check for oil in the coolant. |
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| If equipped, air compressor pumping oil |
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Check/replace air compressor. |
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| High blowby forcing oil out the breather |
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Check the breather tube area for signs of oil loss. Measure the blowby and perform the required repairs. |
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| Turbocharger leaking oil to the air intake |
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Inspect the air crossover tube for evidence of oil transfer. |
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| Worn valve seals |
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Inspect/replace the valve seals. |
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| Piston rings not sealing - oil being consumed by the engine |
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Perform a compression check. Repair as required. |