Why Diesel Engine Fail to Start?

When our generator is used for a long time, it will undoubtedly result in all kinds of problems that lead to generator failure. If your generator fails to start, you can analyze the causes from the following factors.

1. Oil leaks

Diesel engine generators are designed to operate with a load — most effectively in the 70% to 80% range of rated output. When generators operate considerably below the rated output level, the engine can start to over-fuel or “wet stack” which causes damage the engine.

Wet stacking is the accumulation of carbon particles, unburned fuel, lube oil, condensed water and acids in the exhaust system and is caused by low combustion chamber temperature. When a diesel engine wet stacks, the engine will need to be cleaned up by loading the unit for a few hours and burning off excess fuel.

2. Battery Power Shortage

The most common failure for diesel generator is battery failure. Battery failure is commonly the result of low electrolyte levels. To solve the problem, use the battery with sufficient power, or increase the battery to use in parallel. Replace the new start-up battery if necessary. Most often, many battery problems are caused by dirty and loose connections. So the battery maintenance is very necessary.

Attention: the cable connections need to be regularly cleaned and tightened. Besides, you should monitor the charge rates from month to month that will help prevent the failure.

3. Air in the fuel system

This is a common problem with newer generators that are not run on a regular basis. Closer tolerances within the fuel systems to meet today's emission requirements make fuel systems more susceptible to air affecting start up. This is not as common with older generators — many of which may have a leak in a line or check valves that are not properly holding the fuel in the engine.

4. Low coolant levels

This is caused by internal or external leak.

Internally plugged radiator cores will also cause low coolant level shutdowns. When the generator is under load, the thermostats open completely and the radiator cannot allow the proper amount of flow through the core. The coolant has to go somewhere, so it purges through the overflow line.

5. Ran out of fuel

Mechanical fuel level gouges may not always be accurate. Unlike a vehicle that is moving and using a higher percentage of its tank's capacity, a generator tank has no movement, causing the fuel to become stagnant. Mechanical gouges may also stick in a position until vibrations break them free.

Water or moisture in fuel can be damaging to diesel engines because the water properties create advanced ignition and accelerated detonation. If you use fuel polishing as an alternative to cleaning your fuel, check with your vendor to see if its fuel is affected by the chemicals; fuel polishing may not be able to remove water.

Maintenance tips:

Please note that a generator is a mechanical and electrical device that will require service to maintain proper function. Therefore, routine maintenance is very important.

1. Radiator fins should be checked on a monthly basis and cleared of all dirt and debris.

2. Inspect the water pumps for signs of water, bulges, cracking, and leaks.

3. Change fuel filters every 200 to 250 hours, depending on environmental conditions and how clean it is.

4. Make sure the battery and charger connections are tight and clean any corrosion off the terminals. Be sure the battery charger must be turned off before working on the battery or the starter.

5. Check the engine for leaks and wear.

6. Check the engine belts for wear, cracking, or looseness.