Engine Maintenance Chapter 5 Inboard Diesel Engines Part 2

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

3 The Diesel Engine Compression Ignition Compression Ignition Air is heated by compression Air is heated by compression fuel is injected and autoignites fuel is injected and autoignites No spark plug No spark plug

4 Routine Maintenance - Fuel Fuel system Fuel system Primary filter Primary filter Secondary filter Secondary filter Bleeding the system Bleeding the system

5 Fuel System Issues Cleanliness is critical to smooth operation Cleanliness is critical to smooth operation Tanks are vented Tanks are vented Water gets in, even through condensation Water gets in, even through condensation Bacteria grow Bacteria grow Water and sludge get pulled into the fuel system Water and sludge get pulled into the fuel system

6 Fuel System Maintenance A dual filter system is commonly used A dual filter system is commonly used Primary filter Primary filter Low pressure pump Low pressure pump Secondary filter Secondary filter High pressure pump High pressure pump Injector Injector

7 Fuel System Maintenance Primary filter – 30 micron Primary filter – 30 micron Contains a water separator Contains a water separator Secondary filter – 1 micron Secondary filter – 1 micron

8 Cutaway of a Fuel Filter

9 Bleeding the System After servicing, the air must be removed from the system After servicing, the air must be removed from the system Air lock can prevent starting Air lock can prevent starting Fuel is needed to lubricate pump and injectors Fuel is needed to lubricate pump and injectors

10 Bleeding the System Bleed in stages Bleed in stages 1. Use low pressure feed pump to clear the filters 2. Crank the engine to bleed each injector line

11 Routine Maintenance - Cooling Fundamentally the same as gasoline engines Fundamentally the same as gasoline engines May be direct or indirect May be direct or indirect Raw water impeller is the usual suspect Raw water impeller is the usual suspect

12 Routine Maintenance - Lube Fundamentally the same as gasoline engines Fundamentally the same as gasoline engines Use “C” grade oil for diesel service Use “C” grade oil for diesel service

13 Routine Maintenance - Lube Basic reminders: Basic reminders: Check the oil daily Check the oil daily Change oil and filter regularly Change oil and filter regularly Monitor oil pressure Monitor oil pressure Diesels run under high bearing loads Diesels run under high bearing loads 40 to 60 psi at all times 40 to 60 psi at all times 275 to 400 kPa at all times 275 to 400 kPa at all times

14 Check the Obvious Check the Obvious Check the Easy Check the Easy Check Systematically Check Systematically Make No Erratic Adjustments Make No Erratic Adjustments Troubleshooting

15 The fuel system is the most likely cause of failure to start The fuel system is the most likely cause of failure to start Fuel in tank? Fuel in tank? Check for fuel Check for fuel Check for contamination Check for contamination Engine shut off secured? Engine shut off secured? Is the weather very cold? Is the weather very cold? Fuel gelation Fuel gelation Troubleshooting – Fuel

16 Indications Indications Engine stops, temperature gauge reads hot Engine stops, temperature gauge reads hot Check the drive belt on the water pump first Check the drive belt on the water pump first Is it stretched or broken? Is it stretched or broken? A temporary belt can be made from a Nylon belt A temporary belt can be made from a Nylon belt A too hot engine will usually restart after it has cooled A too hot engine will usually restart after it has cooled After restarting check for water exiting from the exhaust After restarting check for water exiting from the exhaust No water exiting, check the water pump for leaking water or broken impeller No water exiting, check the water pump for leaking water or broken impeller If water Is exiting from the exhaust, the prime suspect Is the thermostat If water Is exiting from the exhaust, the prime suspect Is the thermostat Troubleshooting – Cooling

17 Lack of oil Lack of oil Overheating Overheating Worn bearings Worn bearings Fuel dilution of oil Fuel dilution of oil Oil pump wear Oil pump wear Oil pressure gauge malfunction Oil pressure gauge malfunction Troubleshooting – Lubrication

18 Troubleshooting – Glow Plug Check for fuel gelation Check for fuel gelation Check fuses on engine Check fuses on engine If you decide to change the glow plugs: If you decide to change the glow plugs: Keep the seat clean Keep the seat clean Tighten carefully to specification Tighten carefully to specification

19 Remember… You should be able to identify problems and explain them to a mechanic