What are the causes of abnormal noise in diesel engines?
4 Answers
Diesel engine fuel injection pump connecting steel plate is damaged. The following is a relevant introduction about diesel engines: 1. Concept: A diesel engine is an engine that burns diesel fuel to obtain energy release. The advantages of diesel engines are high power and good economic performance. The working process of a diesel engine has many similarities with that of a gasoline engine, with each working cycle also going through four strokes: intake, compression, power, and exhaust. 2. Development prospects: Being bulky, noisy, and emitting black smoke has given many people a poor first impression of diesel engines. After years of research and the application of new technologies, the current state of modern diesel engines is incomparable to the past. Modern diesel engines generally use technologies such as electronic control injection, common rail, and turbocharged intercooling, achieving significant breakthroughs in weight, noise, and smoke levels, reaching the standards of gasoline engines.
As someone who has driven diesel vehicles for over a decade, I've noticed that engine noises are quite common. The fuel injector is the first thing to consider—if it's clogged or worn, unstable oil pressure can cause a ticking sound, especially noticeable during cold starts. Improper valve clearance adjustment is another major cause; if not set correctly, it leads to a metallic knocking noise when the engine is cold, like a small hammer tapping. A loose belt tensioner can produce a squealing sound, often overlooked but quite noisy. Additionally, vibrations in the exhaust system can amplify noises if the mounting bolts are loose. More seriously, bearing issues—such as worn connecting rod or crankshaft bearings—result in a dull sound that becomes prominent during acceleration, often misdiagnosed. I recommend paying attention to noise changes during acceleration or cold starts and addressing issues promptly to prevent minor problems from escalating to engine replacement. After all, while diesel engines are reliable, unaddressed noises can compromise driving comfort and safety.
I often help people with car repairs and believe diesel engine noises can be categorized into minor and severe causes. Issues like belt wear or tensioner looseness produce sharp sounds but cost only a few hundred to replace parts; carbon buildup or clogging in fuel injectors causing ticking noises are also minor fixes requiring cleaning or replacement. However, if the noise is deep and coming from within the engine, it could indicate connecting rod or crankshaft bearing damage, necessitating engine disassembly for repairs costing thousands or even leading to engine scrapping. Exhaust leaks are loud but cheap to fix. Cold-start noises often relate to temperature changes, such as valve clearance issues. My advice: don’t delay upon hearing unusual sounds—check simpler parts first to save money; use high-quality diesel to prevent injector clogging, and change oil regularly to maintain lubrication. These small details can save big money and extend engine life.
Every time my diesel car makes abnormal noises, I worry it might be a safety risk. For example, worn connecting rod bearings can produce knocking sounds, and if severe at high speeds, the engine may stall, leading to loss of control. Faulty fuel injectors causing uneven fuel spray can result in shaking and abnormal noises, affecting steering control. Ignoring accelerating noises from valve train issues may develop into more significant failures. It is recommended to stop the car immediately to check the source of the noise and prioritize sending it to a professional workshop for handling, avoiding risky driving.
