Fault table
12
x =
likely to apply
o =
might apply
1.
Starter motor does not turn engine or only slowly (solenoid switch energises (“click” is audible)
2.
Starter motor turns, engine does not turn
3.
Starter motor turns engine, engine does not start / starts poorly
4.
Ignition failure
5.
Irregular engine running
6.
Engine stalls during operation, no longer starts
7.
Engine “shakes”
8.
Engine only runs at idle speed
9.
Idle speed unstable
10. Engine does not reach its nominal speed
11. Engine does not reach its nominal power
12. Fuel consumption too high
13. Oil consumption too high
14. Engine too “loud” / mechanical noise
15. Heavy blue smoke formation
16. Heavy white smoke formation
17. Exhaust temperature / exhaust back pressure too high (thermal overload)
18. Lubrication oil pressure too low
19. Temperature difference engine exit / engine entry too great
20. Coolant temperature too high
Possible causes
x
Batteries discharged, battery cable connections loose or corroded, power circuit inter-
rupted
x
Starter motor defective (carbon brushes loosened / worn, coil damaged, ground fault)
x
Engaging lever / bearing bolt of the engaging lever broken
x
Crankshaft drive blocked
x
x
Engine oil viscosity unsuitable, not suited to ambient temperature
x
Ignition control unit defective
x
Impulse sensor defective / gap incorrectly set
x x
x
Spark plug defective
x x
x
Ignition cable defective
x x
x
Ignition coil defective
o
o
x x x
x
Ignition point incorrectly set
x
Throttle valve does not open / actuating rod jammed / setting unit de-energized or defec-
tive
x x
Throttle valve not in full-load position / actuating rod jammed / throttle valve incorrectly
adjusted
x
x
Shut-off solenoid valve of gas supply closed / does not open
x
x
Zero pressure regulator of gas supply not correctly set or defective
x x x
Gas metering valve defective
x
x x
Gas / air mixture too rich or too lean
x
x
Lack of compression, or more than 3 bar pressure difference between the individual cylin-
ders
x
x
x
x
Valve clearance not correct
x
x
Valve guides heavily worn
x
x
x
x
Valve seats leaking
x
x
x
x x
Piston rings heavily worn, broken (overpressure in the crankcase)
x x x x
Air filter heavily soiled
x x x
Charge mixture cooler soiled / leaking
x x x
Charge mixture piping leaking
x x
Turbine and compressor wheel in the turbocharger soiled (running off balance)
x
Coolant entering combustion chamber (cylinder head gasket leaking)
x
Engine in cold running phase
x
x
Crankcase breather blocked
x
Oil level in oil pan too high
x
Safety valve in the oil circuit defective (does not close, spring fatigued or broken)
x
Heavy bearing wear
x
Oil pump heavily worn
x
Safety valve in the oil circuit defective (does not open), oil lines / oil ducts blocked
x
Unsuitable exhaust-gas piping, heat exchanger and catalytic converters with excessive
resistance
x
Flow resistance of cooling system too great
x x Soiling of cooling system
Summary of Contents for E 2942 LE 302
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