Regardless of how much humans ignore their own hearts, the same cannot be said for the cherished mechanisms propelling their essential work. Still, the engine, the heart of the diesel generator, is not immune to issues. 

Basic knowledge of the obvious problems of engines and the ability to combat them with solutions has the potential to aid in taking timely steps toward maintenance. For temporary solutions, too, the information is helpful. So, to enlighten all the diesel generator owners, here is an insight into why your diesel generator cranks but won’t start. Worry not, we have offered measures to fix it as well. Let’s dive in!

Reasons for Diesel Generator Cranking But Not Starting

There can be a multitude of reasons for the problem, including: 

  • Battery: Responsible for initiating the engine-starting process through the starter motor; a dead or weak battery can lead to the situation. Possible causes include corrosion, flattening, or a broken connection. Additionally, lead-acid batteries may be diluted due to water.
  • Starter Motor: As the prime component that turns over the engine, any faults or wear may halt the process at the initial step.
  • Fuel System: Critical for the flawless operation of any engine, even a slight issue with the fuel system can prevent starting. Possible situations include clogging through air bubbles or debris in the fuel filter, air disallowing proper flow, an empty fuel tank, dilution due to water, or the presence of debris. Fuel pipes may also be clogged, cracked, ruptured, bent, or constrained, cutting off the fuel supply.
  • Air Intake: Engines require proper air intake for smooth operation. Restricted airflow due to debris or dirt clogging can be a potential cause of cranking without starting.
  • Engine: Checking the engine itself for the proper functioning of the block heater, coolant, and engine oil is an easy method for identifying potential problems.
  • Glow Plugs: Problems with glow plugs are more likely during cold weather. They function to warm the combustion chamber for the engine to start. The inability to heat the chamber properly can result in the engine not starting.

Fixing Diesel Generator Problems 

Now, let us explore what you can do to solve the problem:

Battery: Inspect the battery for its charging level and delivery voltage. Use a multimeter for this purpose. Also, check for signs of water or fluid leakage, damage, or corrosion. 

Start motor: You have to check if the starter motor engages and turns the engine properly or not. 

Fuel system: Based on the listed problems, check accordingly. Ensure the absence of debris, proper shape, and presence of clogging through air bubbles or debris. Bleed the fuel to remove air bubbles and unclog for removal of debris. Also, cross-check the fuel level and leakage. 

Air intake: Look for dirt and debris on the air filter. Clean it thoroughly and inspect for any signs of leakage or damage. 

Glow plugs: Use a multimeter to check the functionality of glow plugs and eliminate the reason for fault. 

Besides the above solutions based on the mentioned causes, there can be other measures as well. Have a look at them as well: 

Solenoid: An issue with the solenoid will impede fuel movement to the injector. The only option is to replace the solenoid. 

Silencer: It can have holes or can be clogged due to birds blocking the airflow. Replace the silencer as per the situation.

Fuel: For long-unused generators, fuel may become contaminated or lose viscosity, leading to increased thickness. In such cases, fuel replacement and thorough system inspection are necessary. 

Bund alarm: Check the surrounding area, bund alarms, and bunded fuel tank. It should not have leaked fuel, which can lead to the situation of cranking but not starting. Proper cleaning is the solution. 

Louvers: The moisturized louvers can have problems like rusting that impairs its opening. Further, the louver motor should be functional. Lubricate the louvers to ensure free opening and ensure the motor is functioning properly.

Generator Load Bank

Top Companies Offering Diesel Generators

Combining a proper maintenance schedule and the generators from a top company, you can minimize the frequency of expecting such problems. So, here are the top four companies to consider for seamlessly functioning diesel generators. In case of still facing the problem, we have you covered further: 


Being the leading manufacturer, Cummins diesel generators are offered to meet all types of requirements. Their servings are for residential, commercial and industrial applications in desired fuel types. Learn how to fix Cummins generator issues


Serving for more than 90 years, their quality has been unmatchable. Besides diesel generators of and for all types, the brand also offers construction and mining equipment, gas turbines, gas engines, and locomotives. Discover quick steps on how to fix Caterpillar Generators that won’t start.  


They have proved their mettle in manufacturing backup power generators for all purposes. They offer a variety suiting the varying needs of customers. They are famous for quality generators at affordable costs. Further, they are also known for smooth operation and durability. If your Generac generator is causing you trouble, here’s how you can fix it quickly. 


Serving the industry since 1920 with their family-owned business of generator production, they are the oldest company. They are also concerned with producing plumbing products, engines, and furniture. Kohler is known for high-end products and innovative technology with outstanding reliability. Learn in detail about the quick steps to fix the Kohler Generator that doesn’t start. 

Diesel Generator

Replace Your Generator With CS Diesel 

Diesel generators are an important solution to all the power problems. Owning long life with proper maintenance, you can have them either serviced on facing an issue or choose to replace it. In case of high servicing costs, the second option is the recommended one. Looking for a new generator, or do you face budget constraints? We also provide used generators with complete transparency on their features and condition. Explore the wide variety of our range with quality delivery service from CS Diesels.  

Common Questions About Inoperative Generators 

Q1. What are the other possible issues with the generator other than cranking but not starting?

The generator might not even crank. It may start but shut down, run unevenly, and then stop, and it can also start and run but be unable to produce electricity. 

Q2. What does it mean by bad fuel mix? 

The bad fuel mix refers to the improper concentration of fuel. There are four possibilities resulting from the situation. These are: 

  • The engine receives only air and not fuel. It occurs when there is no fuel. 
  • The engine receives only fuel but not air. The clogged air intake is the problem. 
  • Engine receiving improper fuel concentration with too high or too little fuel. The problem occurs in combustion. 
  • The engine receives impure fuel contaminated with water or debris. Long-standing fuel is the reason, and replacement is the solution here. 

Q3. Enlist preventive measures to ensure non-stop running of diesel generator engines. 

The recommended preventive measures include regular and thorough maintenance of all components of diesel generators. Also, actions must be taken to ensure proper fuel storage and maintaining its integrity. 

Q4. What is the life of the engine of a diesel generator?

The diesel generator engine can last anywhere between 15,000 to 50,000 working hours. The life span depends on multiple factors. 

Q5. Can diesel generators run nonstop?

Yes, diesel generators are capable of continuous running depending on conditions like the presence of fuel and other factors.