Engine Maintenance Chapter 5 Inboard Diesel Engines Part
Engine Maintenance Chapter 5 Inboard Diesel Engines Part 2
Objectives for the Student 1. Have knowledge of routine maintenance procedures for diesel engines 2. Have an understanding of troubleshooting techniques for fuel, cooling, and lubrication systems 2
The Diesel Engine n Compression Ignition n Air is heated by compression fuel is injected and autoignites No spark plug 3
Routine Maintenance - Fuel system n Primary filter n Secondary filter n Bleeding the system n 4
Fuel System Issues Cleanliness is critical to smooth operation n Tanks are vented n Water gets in, even through condensation n Bacteria grow n Water and sludge get pulled into the fuel system n 5
Fuel System Maintenance n A dual filter system is commonly used Primary filter n Low pressure pump n Secondary filter n High pressure pump n Injector n 6
Fuel System Maintenance n Primary filter – 30 micron n n Contains a water separator Secondary filter – 1 micron 7
Cutaway of a Fuel Filter 8
Bleeding the System n After servicing, the air must be removed from the system n Air lock can prevent starting n Fuel is needed to lubricate pump and injectors 9
Bleeding the System n Bleed in stages 1. 2. Use low pressure feed pump to clear the filters Crank the engine to bleed each injector line 10
Routine Maintenance - Cooling Fundamentally the same as gasoline engines n May be direct or indirect n Raw water impeller is the usual suspect n 11
Routine Maintenance - Lube Fundamentally the same as gasoline engines n Use “C” grade oil for diesel service n 12
Routine Maintenance - Lube n Basic reminders: the oil daily n Change oil and filter regularly n Monitor oil pressure n Check n Diesels run under high bearing loads n 40 to 60 psi at all times n 275 to 400 k. Pa at all times 13
Troubleshooting n n Check the Obvious Check the Easy Check Systematically Make No Erratic Adjustments 14
Troubleshooting – Fuel The fuel system is the most likely cause of failure to start n Fuel in tank? n n Check for fuel n Check for contamination Engine shut off secured? n Is the weather very cold? n n Fuel gelation 15
Troubleshooting – Cooling n Indications n n Check the drive belt on the water pump first n n n Engine stops, temperature gauge reads hot Is it stretched or broken? A temporary belt can be made from a Nylon belt A too hot engine will usually restart after it has cooled n n n After restarting check for water exiting from the exhaust No water exiting, check the water pump for leaking water or broken impeller If water Is exiting from the exhaust, the prime suspect Is thermostat 16
Troubleshooting – Lubrication Lack of oil n Overheating n Worn bearings n Fuel dilution of oil n Oil pump wear n Oil pressure gauge malfunction n 17
Troubleshooting – Glow Plug Check for fuel gelation n Check fuses on engine n If you decide to change the glow plugs: n n Keep the seat clean n Tighten carefully to specification 18
Remember… You should be able to identify problems and explain them to a mechanic 19
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