Diesel Distress: Why Your Engine Struggles to Start

That sinking feeling when you turn the key and your diesel engine just...churns. A struggling start is a common diesel ailment, especially in colder climates, and it can stem from a variety of causes.


Glow Plug Problems:

  • The Crucial Pre-Heat: Glow plugs are essential for diesel cold starts. They heat the combustion chamber, allowing the fuel-air mixture to ignite. In colder weather, faulty glow plugs are a prime suspect for hard starts.
  • Testing and Replacement: Glow plugs can be tested with a multimeter, and replacing them is often a straightforward job.


Fuel System Issues:

  • Fuel Starvation: A clogged fuel filter, a failing fuel pump, or air in the fuel lines can restrict fuel flow, making it difficult for the engine to start.
  • Even low fuel levels can cause issues on steep inclines.
  • Fuel Injector Problems: Dirty or malfunctioning fuel injectors can deliver an incorrect fuel spray pattern, leading to poor combustion and hard starts.
  • Water in the fuel can also damage injectors.
  • Fuel Quality: Using low-quality diesel fuel, especially in cold weather, can cause starting problems. Cold weather can also cause gelling in the fuel.


Battery and Starter Issues:

  • Weak Battery: A weak battery might have enough power to crank the engine, but not enough to provide the necessary spark for ignition.
  • Cold weather reduces battery capacity.
  • Faulty Starter: A failing starter motor might not crank the engine fast enough for proper combustion.


Compression Problems:

  • Worn Piston Rings or Valves: Worn piston rings or valves can lead to poor compression, making it difficult for the fuel-air mixture to ignite. This is more common in older engines.
  • Head Gasket Issues: A blown head gasket can also lead to compression loss.


Sensor Problems:

  • Crankshaft Position Sensor: A faulty crankshaft position sensor can provide incorrect information to the engine control unit (ECU), preventing the engine from starting.
  • Temperature Sensors: Faulty coolant or fuel temperature sensors can cause the ECU to provide incorrect fuel ratios.



Air Intake Problems:

  • Clogged Air Filter: A heavily clogged air filter can restrict airflow, making it difficult for the engine to start.
  • Air leaks: Air leaks in the intake system can also cause starting problems.


Preventive Maintenance:

  • Regular Oil Changes: Use high-quality diesel engine oil and change it according to the manufacturer's recommendations.
  • Fuel Filter Replacement: Change the fuel filter regularly to prevent fuel contamination.
  • Glow Plug Maintenance: Check and replace glow plugs as needed, especially before cold weather sets in.
  • Battery Maintenance: Ensure your battery is in good condition and replace it as needed.
  • Use Quality Fuel: Use good quality diesel fuel, and in cold climates use fuel additives to prevent gelling.


Give us a call and let us take care of you.


Happy Adventures,

Heather


Our specials can be found here - Specials - J & H Automotive, Inc 

Ready to make an appointment … Appointments - J & H Automotive, Inc 

Want to know more … About Us - J & H Automotive, Inc 

Would you like to join our merry band of misfits? Careers - J & H Automotive, Inc 


 
Want to know more…

https://www.facebook.com/JHAutomotiveInc                   

https://www.pinterest.com/jhautoinc

Instagram photos and videos

LinkedIn
 


By jhautoinc January 30, 2026
These are vital to keep you safe on the road.
By jhautoinc January 27, 2026
Your engine will thank you.
By jhautoinc January 23, 2026
They help keep your engine cool.
By jhautoinc January 20, 2026
They need maintenance to keep them running.
By jhautoinc January 17, 2026
It's better for your engine. 
By jhautoinc January 13, 2026
They are more important than you know.
By jhautoinc January 10, 2026
A spark plug gap can cause a misfire.
By Bobby Poist January 7, 2026
They're important to keep you safe on the road.
By jhautoinc January 3, 2026
It's more often than you think.
By jhautoinc December 31, 2025
Batteries really don't like cold weather