Diesel engine runaway is one of the most dangerous malfunctions that can occur for diesel engines. When your diesel starts to runaway, it can lead to catastrophic failure and damage. Understanding what causes this issue and recognizing the warning signs early can save you from expensive repairs or even engine replacement. Here’s what you need to know about diesel engine runaway and how to prevent it.
What Causes Diesel Engine Runaway?
Diesel engine runaway happens when an engine starts to consume more fuel than the throttle is set for, leading to uncontrolled revving and possible engine failure. This can be caused by factors such as hydrocarbons in the air, as well as paired with age-related wear and tear or the accumulation of debris in the air intake system or turbocharger. In older diesel engines, oil leaks from the turbo or overfilled crankcases could also act as fuel sources when oil enters the combustion chamber, causing the engine to rev uncontrollably and requiring a shut off valve to prevent catastrophe.
How Often Should Diesel Engines Be Maintained?
Regular maintenance is crucial to the health of any diesel engine, especially those that are frequently used in demanding environments such as industrial, mining, and oil and gas sectors. Diesel engines should generally undergo maintenance every 5,000 to 7,500 miles (8000 to 10,000km), or 250 to 500 hours of use, though this can vary depending on the manufacturer and engine model. Keeping up with oil changes, air filter replacements, and inspecting the fuel system can help prevent serious issues, including the risk of a runaway.
Can a Diesel in Need of Maintenance Lead to Runaway?
Yes, a diesel engine that hasn’t been properly maintained is more vulnerable to runaway. Without routine upkeep, oil leaks, faulty turbochargers, or clogged air filters can lead to the introduction of unregulated fuel into the combustion chamber, which can spiral into a runaway situation. The longer maintenance is delayed, the higher the risk becomes.
7 Signs Something Is Wrong with Your Diesel Engine
Being aware of the early signs that something may be wrong with your diesel engine is critical in preventing a runaway. Here are seven warning signs to watch for:
1. Excessive Black Exhaust
Black, thick exhaust is a clear indicator of an imbalance in the air-to-fuel ratio. Black smoke typically suggests too much fuel is being burned, which could signal that your engine is under stress.
2. Increased Noise and Revving Sounds
If your diesel engine starts making louder than normal sounds, especially a high-pitched revving noise, this could be an early warning of an impending runaway.
3. Blue Smoke
Blue exhaust smoke points to oil burning in the combustion chamber. This could be due to an oil leak in the turbocharger or other engine components. Not only is blue smoke a sign that your diesel is in danger, but it signals a higher risk of diesel engine runaway.
4. Starting Problems
Difficulty starting the engine may suggest a fuel system or compression issue. Persistent starting problems should be checked by a professional, as they may indicate underlying engine problems.
5. Poor Fuel Efficiency
A noticeable decrease in fuel economy could mean your engine is working harder than it should, potentially signaling an issue with fuel injectors, turbochargers, or even compression leaks.
6. Loss of Power
When your engine struggles to maintain power or respond to throttle input, this could indicate several problems, including insufficient fuel delivery, air intake issues, or a clogged exhaust system.
7. Rough Idling
A diesel engine that idles roughly could be experiencing a variety of problems, from worn fuel injectors to improper air intake. This rough idling could escalate into more severe engine issues if left unchecked.
Preventing Diesel Engine Runaway
To avoid the risk of diesel engine runaway, regular maintenance of your diesel engine is essential. Scheduling routine inspections and repairs ensures that oil leaks, air intake problems, and other common issues are identified and resolved early. Additionally, installing a diesel engine shut-off valve can automatically cut off the air supply and stop the engine if a runaway starts. And, of course, always pay attention to any unusual signs your engine is giving you — acting early can make all the difference.
Contact Headwind Solutions to install the ShockerPASS for your diesel engine, the ultimate defence against diesel engine runaway.