Exhaust valve damaged Problem for Diesel Engine

General Damage

1. Exhaust valves 'O' ring damage occur
2. Roto cap stacked
3. Tiny gap between valve and valve seat

Possible Causes

1. High exhaust gas temperature
2. Failure of cooling system
3. Valve get corrosion by friction
   

Maintenance Work 

1. Change the 'O' rings
2. Use high temperature resistant grease around 'O' rings
3. Do Lapping operation in valve and valve seat interface surface until they adjusted correctly






4. Control the exhaust gas temperature

Extreme Damage 

1. Valve get bended 
2. Valve get broken
3.  Some parts of the valve melt down

Possible Causes

1. Engine runs long time with high exhaust gas temperature 
2. Failure of cooling system
3. Auto ignition take place in different times



Valve bended

4. The material of exhaust valve is not perfect(can't withstand long time in high temperature)

Maintenance Work 

1. Change the valve
2. Control the exhaust gas temperature
3. Use a valve constructed with proper composition of metals
   

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