Cylinder Head Blown Sealing Ring.

[Anonymous]

Has anyone experienced a blown cylinder head sealing ring?.

We just had an incident on Engine 5 A6 Cylinder Head with 7050Hrs. Cylinder Head has never been replaced before.

The first alarm was a sensor fault on the HT/LT Cooling system pressure, then after almost 2 minutes ALM High HT Water temperature jacket outlet in the A-Bank. This second alarm tripped the engine on temperature. Looking at the trends the Cooling system pressure went from 55psi to 85psi in about 15 seconds.

Operator walked the engine and noticed the expansion tank throwing away a lot of water. The electrical panels BJA, ALOF,HT,LT and oil mist separator were all washed with cooling water falling from the expansion tank. Fortunately no water penetrated inside the panels.

During the troubleshooting it was found Cylinder Head A6 Full of water. A7,A8 and A9 have some accumulation on top of the piston crown and same with B7,B8,B9. The PCC line was found with water as well.

All pistons were inspected by straightness an non of them showed signs of bending.

All CH Prechambers inspected for leaks. All found ok.

All CH Inspected for tightness and A7,A8,A9,B7,B8,B9 showed some leakage to the intake side. These heads were inspected through a cooling port plug to make sure the sealing ring between the head and liner was in place and didn’t have any issue. Heads were confirmed with no further issues on the cooling side.

Cylinder A6 Upper Rod, Piston, Liner and CH were replaced.

All the LO Batch was replaced.

Cooling system was filled and engine pressure tested. No issues found.

Engine oil was filled and engine was tested successfully. Some pockets of water had to be vented during the starts since they caused some issues in the first attempts.

Running in program was performed successfully and the engine dint show any other symptom.

Engine is back on service and further investigation about the root cause is on going.

 

[Author]

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