Analysis of Excessive Crankcase Ventilation in Yuchai Diesel Engines

Neglecting the issue of excessive crankcase ventilation in Yuchai diesel engines can lead to serious damage and even premature failure of the unit.

Causes of Excessive Crankcase Ventilation

Excessive crankcase ventilation in Yuchai diesel engines can stem from several causes, and blind disassembly for overhaul should be avoided. This issue is typically a result of early wear and is primarily related to the following three aspects: excessive internal leakage in the turbocharger, severe wear of the air compressor, and for engines that have undergone overhaul, incorrect clearances and assembly (such as piston ring misalignment, improper fitting clearances, or damaged cylinder head gaskets). Therefore, attention to daily maintenance of Yuchai diesel engines is crucial.

Severe crankcase ventilation, accompanied by decreased engine power and possibly blue smoke, may indicate serious wear of piston rings and cylinder liners, piston crown ablation, or cylinder scuffing. These issues compromise the seal between the piston rings and cylinder liners, allowing large amounts of compressed gas to enter the crankcase through the small gaps during the compression and expansion strokes, thereby increasing crankcase pressure. In such cases, at least a mid-overhaul is required. For specific conditions, it is advisable to consult the manufacturer, Dingbo Power, to disassemble the engine for assessment.

Incorrect installation of piston rings, particularly ring misalignment where all ring gaps are aligned, can cause problems even if the rings are not worn. This misalignment can lead to ring sticking, breakage, or loss of elasticity, all of which result in poor cylinder sealing. Combustion gases then leak into the crankcase, increasing pressure. The solution is to disassemble and reinstall the piston rings correctly.

Severe wear of the air compressor piston rings can cause compressed air leakage. The compressed air flee to the engine crankcase through the air compressor's crankshaft connecting rod mechanism, leading to increased crankcase ventilation. For engines equipped with an air compressor, this possibility should be considered when excessive crankcase ventilation occurs. However, this situation does not cause a decrease in engine power but results in insufficient compressed air from the compressor. Additionally, take apart the air lines will reveal the presence of engine oil. The solution is to repair or replace the air compressor.

Guangxi Dingbo Generator Set Manufacturing Co.,Ltd. was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. The company has a registered capital of 218.88 million yuan. The company covers an area of 86,000 square meters and a building area of 55,000 square meters. There are more than 660 employees, including 456 professional technicians and 106 senior technicians. It has 46 sales and service outlets nationwide. The main products are diesel engines, generator sets, and diesel generators, providing users with a one-stop service of design, supply, debugging and maintenance at any time. Dingbo has always insisted on using first-class talents, building first-class enterprises, manufacturing first-class products, creating first-class services, and making every effort to build a first-class domestic enterprise. If any question please feel free to visit our website https://www.dieselgeneratortech.com/ or send email to [email protected].