Fault Tracing; Symptoms And Possible Causes - Volvo TD420VE Operator's Manual

Fault tracing

A number of symptoms and possible causes of engine malfunctions are described in the table below. Always
contact your Volvo Penta dealer if any problems occur which you can not solve by yourself.
WARNING! Read through the safety advice for care and maintenance work in the "Safety information"
chapter before starting work.

Symptoms and possible causes

The diagnosis button lamp flashes.
Engine can not be stopped.
Starter motor does not rotate
Starter motor rotates slowly
Starter motor rotates normally but engine does not start
Engine starts but stops again
Engine does not reach correct operating speed at full throttle 9, 10, 11, 12, 13, 21, 25, 26
Engine runs roughly
High fuel consumption
Black exhaust smoke
Blue or white exhaust smoke
Too low lubrication oil pressure
Excessive coolant temperature
Too low coolant temperature
No, or poor charge
1. Flat batteries
2. Poor contact/open circuit in
cables
3. Main switch turned off
4. Faulty ignition lock
5. Faulty main relay
6. Faulty starter motor relay
7. Faulty starter motor/solenoid
8. Lack of fuel:
– fuel taps closed
– fuel tank empty/wrong tank
connected
9. Blocked fuel filter/pre-filter
(because of contamination, or
paraffin fraction separation in
fuel at low temperature).
36
Please refer to the "Diagnostic information" chapter.
10. Air in the fuel system
11. Water/contamination in fuel
12. Faulty injection pumps
13. Insufficient air supply to en-
gine:
– blocked air filter
– air leakage between turbo-
charger and engine inlet pipe.
– fouled compressor section in
turbocharger
– faulty turbocharger
– poor engine bay ventilation
14. Excessive coolant temperature
15. Too low coolant temperature
16. Too low oil level
17. Coolant level too low
2, 4
1, 2, 3, 4, 5, 6, 7, 24
1, 2
8, 9, 10, 11
8, 9, 10, 11, 13
10, 11, 27
12, 13, 15, 25
12, 13
14, 15, 22
16
17, 18, 19, 20
20
2, 23
18. Air in the coolant system
19. Faulty circulation pump
20. Defective thermostat
21. Blocked intercooler
22. Too high oil level
23. Alternator drive belt slips
24. Water entry into engine
25. High back pressure in exhaust
system
26. Break in "Pot+" cable to pedal
27. Incorrectly set engine speed
regulator / actuator