Analisis Kerusakan Engine High Blow-By Pressure pada Mesin Diesel Unit Excavator Caterpillar 320Gc di PT PP Presisi Tbk.

Pandhu Khanif Pramudya, Ir. Surojo, S.T., M.Eng,. IPM.

2025 | Tugas Akhir | D4 TEKNIK PENGELOLAAN DAN PERAWATAN ALAT BERAT

Penelitian ini menganalisis kerusakan engine high blow-by pressure pada unit excavator Caterpillar 320 GC di PT PP Presisi Tbk.  Kerusakan ini ditandai dengan penurunan tenaga mesin (low power) dan munculnya asap putih dari muffler serta crankcase breather. Analisis dilakukan melalui beberapa metode, termasuk pengukuran tekanan blow-by, pengujian Schedule Oil Sampling (SOS), pembongkaran mesin (overhaul), dan analisis akar masalah (Root Cause Analysis) dengan diagram fishbone, 5W+1H, dan fault tree analysis (FTA)

Hasil penelitian menunjukkan bahwa tekanan blow-by mencapai 2,72 inH?O, yang mengindikasikan kondisi mesin yang buruk. Analisis oli (SOS) mendeteksi konsentrasi wear metal yang tinggi, terutama besi (Fe) sebesar 97.2 ppm, yang menandakan adanya keausan parah pada komponen internal mesin. Setelah dilakukan overhaul, ditemukan keausan yang signifikan pada cylinder liner, piston, dan ring piston yang melebihi batas toleransi standar.

Penyebab utama dari high blow-by pressure adalah keausan pada ring piston, piston, dan cylinder liner akibat peningkatan kandungan wear metal dan kontaminasi oli oleh bahan bakar (fuel dilution) yang mengurangi efektivitas pelumasan, di mana kondisi ini dipicu oleh kombinasi faktor seperti kurangnya pelatihan operator, ketidaktepatan prosedur pemeliharaan, tidak adanya sistem pemantauan dini yang memadai, serta kondisi lingkungan kerja yang ekstrem, yang pada akhirnya menyebabkan kerusakan mesin diesel dan mengakibatkan unit mengalami kekurangan tenaga (low power).

Solusi yang direkomendasikan adalah melakukan penggantian komponen yang aus (cylinder liner, piston, dan ring piston), meningkatkan pelatihan bagi operator, dan menerapkan jadwal perawatan preventif yang lebih ketat untuk mengembalikan performa mesin dan memperpanjang umur komponen.

This study analyzes engine damage characterized by high blow-by pressure on a Caterpillar 320 GC excavator unit operated by PT PP Presisi Tbk.

The damage is indicated by reduced engine power (low power), along with the emission of white smoke from the muffler and crankcase breather. The analysis was conducted using several methods, including blow-by pressure measurement, Scheduled Oil Sampling (SOS) analysis, engine disassembly (overhaul), and root cause analysis through fishbone diagrams, the 5W+1H method, faul tree analysis (FTA)

The results showed that the blow-by pressure reached 2.72 inH?O, indicating a deteriorated engine condition. Oil analysis (SOS) detected high concentrations of wear metals, particularly iron (Fe) at 97.2 ppm, suggesting severe wear on internal engine components. After the overhaul, significant wear exceeding standard tolerance limits was found on the cylinder liner, piston, and piston rings.

The primary cause of the high blow-by pressure was identified as wear on the piston rings, pistons, and cylinder liners due to increased levels of wear metals and oil contamination by fuel (fuel dilution), which reduced lubrication effectiveness. This condition was triggered by several contributing factors, including insufficient operator training, improper maintenance procedures, lack of adequate early detection systems, and extreme working environment conditions. As a result, the engine suffered damage and experienced a significant loss of power.

The recommended solutions include replacing the worn components (cylinder liner, piston, and piston rings), improving operator training, and implementing a stricter preventive maintenance schedule to restore engine performance and extend component lifespan.

Kata Kunci : Kebocoran Tekanan, Caterpillar 320Gc, Mesin Diesel, Root Causes Analysis,Keausan koponen engine