ONL773LW4 5/21
25
Troubleshooting
ENGINE
PROBLEM
POSSIBLE CAUSE
RECOMMENDATION(S)
Lack of Engine Power
Improper type of fuel
• Consult fuel supplier and use proper type of
(continued)
fuel for operating conditions.
Overheated engine
• See “Engine Overheats” in next category.
Below normal engine temperature • Remove and check thermostat.
Improper valve clearance
• Reset valves. Best done by dealer.
Dirty or faulty injection nozzles
• Replace injectors. Best done by dealer.
• See your local dealer.
Poor cylinder compression pressure • Check bore for wear, or check alignment of
nozzle holder. Re-adjust valve clearance.
Engine Overheats
Low coolant level
• Fill tank or radiator to proper level, with
proper mixture of coolant.
• Check hoses for loose connections
and leaks.
Air cleaner element clogged
• Clean or replace.
Cooling system interior dirty
• Flush cooling system.
Defective thermostat
• Remove and check thermostat.
Defective temperature gauge
• Check water temperature with thermometer
and replace gauge if necessary.
Water pump impeller worn/broken • Check impeller and replace if necessary.
V belts slipping
• Fix belts to proper tension.
Engine Knocks
Insufficient oil
• Call your dealer.
Injection pump timing off
• Call your dealer.
Below normal engine temperature • Check your thermostats.
• Check water temperature to see if
temperature gauge is working properly.
Engine overheating
• See “Engine Overheating” section.
High Fuel Consumption
Improper type of fuel
• Use correct fuel for temperature.
Clogged or dirty air cleaner
• Service air cleaner.
Improper valve clearance
• See your dealer.
Injection nozzles dirty
• See your dealer.
Injection pump timing off
• See your dealer.
Engine not at proper temperature • Check your thermostats.
• Check water temperature with thermometer
and replace gauge if necessary.
If you cannot correct problems with these procedures, see your
Northern Lights
dealer.
