High Crankcase Pressure in Diesel Engine
A much higher than normal reading on the engine crankcase pressure gauge indicates a potential problem that needs immediate attention. Here’s a breakdown of the implications, actions to take, and potential causes:
(a) Implications and Immediate Actions:
- Increased Blow-by Gases: High pressure suggests excessive blow-by gases (unburnt fuel and air) are leaking past the piston rings into the crankcase. This can lead to:
- Reduced Engine Power: Excessive blow-by reduces the pressure available for combustion, impacting engine performance.
- Oil Dilution: Blow-by gases can contaminate the engine oil, reducing its lubricating properties.
- Fire Hazard: Oil mist from the crankcase can create a fire hazard near hot engine components.
Immediate Actions:
- Reduce Engine Load: Gradually decrease engine load and prepare for a safe shutdown.
- Investigate the Cause: Do not ignore the issue. Identify the reason behind the high pressure.
- Alert Personnel: Inform relevant personnel, especially maintenance or supervisory staff, about the situation.
- Do Not Restart: Avoid restarting the engine until the cause is identified and addressed. Running the engine with high crankcase pressure can lead to serious damage.
(b) Checks and Investigations:
To determine the cause of the increased pressure, conduct the following checks and investigations:
- Piston Rings: Check for worn, damaged, or broken piston rings, which can allow excessive blow-by.
- Cylinder Liners: Inspect cylinder liners for scoring or wear, which can contribute to blow-by.
- Valve Train: Examine valve clearances and for any signs of sticking valves, as improper sealing can lead to blow-by.
- Fuel Injectors: Investigate the condition of fuel injectors. A faulty injector can deliver too much fuel, resulting in incomplete combustion and increased blow-by.
- Crankcase Ventilation System: Ensure the crankcase ventilation system is not clogged, as a blocked system traps blow-by gases.
- Oil Level and Condition: Check the oil level and condition. Low oil level can increase blow-by, and contaminated oil may not properly lubricate piston rings.
By systematically examining these potential causes, you can identify the source of the high crankcase pressure and take corrective actions to ensure safe and efficient engine operation.