Man D 2840 LE 301, Repair Manual

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Troubleshooting table
13
1. Starter turns over engine only slowly or not at all
2. Starter turns, engine does not start, engine does not start / difficult to start when cold
3. Engine stalls (dies) during operation, no longer starts (starter turns),
engine does not start / starts with difficulty when hot
4. Sudden, temporary engine shutdown, engine does not reach full revs
5. Engine only runs at idle speed, no throttle response
6. Engine only runs at increased idle speed, no throttle response
7. Rated engine speed distinctly reduced (even under no load)
8. Reduced output in all ranges
9. Irregular engine operation, traction loss
10. Unstable idle speed, engine hunting, misfiring, knocking in engine
11. Engine judder
12. Unusual combustion noise
13. Excessive smoke emission: White smoke / blue smoke
14. Excessive smoke emission: Black smoke
15. Engine temperature too high (coolant loss)
16. Intermediate speed control cannot be activated / does not switch off;
engine running at an excessively high speed
17. Fuel consumption too high
18. Lubricating oil pressure too low
19. Lubricating oil pressure too high
20. Lubricating oil consumption too high
21. Engine too “loud” / mechanical noise
Possible causes
x x x x x x x Fuel low pressure system: Air in system (turn on ignition when bleeding system)
x x x x x x x x x Fuel low pressure system: Fuel pump, overflow valve, main filter
x x x x x o x x Fuel high pressure system: Jets defective / clogged / leaking / coked
x x x x o Fuel high pressure system: Pressure lines − constriction, cavitation, leaking
x x o x x x x o Fuel high pressure system: Injection pump worn / set incorrectly
o x o o Fuel high pressure system: Injection pump constant-pressure control
valve / return flow restrictor defective
o o o x o x x x Injection pump-engine allocation: Start of delivery incorrect (basic installation),
start of delivery set incorrectly
x x x o Both rpm sensors defective, line defective
x x o x Exhaust turbocharger leaking or defective
x Turbine and compressor rotor in turbocharger dirty (out-of-balance, irregular running)
x Intercooler leaking, defective
x x Flame starter defective
x x Radiator dirty or failure of cooling system (temperatures too high)
x Coolant level too low, air in coolant circuit
x V-belt for water pump drive not tensioned correctly
x x Incorrect V-belt tension
x Water pump leaking, defective / Thermostat defective, does not open
x Coolant lines leaking, clogged or twisted
x Coolant entering combustion chamber (cylinder head / gasket leaking)
x Engine bearings worn