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How do I troubleshoot the noise coming from my diesel engine?

Posted by Alex Smith on

Much like a human body, a vehicle exhibits certain symptoms when it’s sick. Some are cut and dried, like an engine knock alerting you to a low oil level. Other symptoms, however, can indicate far more complex issues. Global diesel aficionados offered several tips on how to understand what your car is telling you by the sounds it makes. Read on to learn more.

Vedran Krampelj

Vedran Krampelj

Vedran Krampelj, Owner of Car Horizon.

Check for Loose or Damaged Parts

There are a few steps you can take to troubleshoot the noise coming from your diesel engine:

    ● Determine the source of the noise: Is the noise coming from the front, back, or middle of the engine? Is it a constant noise or does it come and go? Does the noise change when you rev the engine or when you put the vehicle in gear? This information will help you narrow down the possible causes of the noise.

    ● Check for loose or damaged parts: Inspect the engine and look for any loose or damaged parts that may be causing the noise. This includes things like belts, hoses, and exhaust components.

    ● Check the engine oil level: Low engine oil levels can cause noise and damage to the engine. Make sure the oil level is at the proper level and consider changing the oil if it is dirty or has been in the engine for a long time.

    ● Check the engine coolant level: Low coolant levels can cause the engine to overheat and make noise. Make sure the coolant level is at the proper level and consider flushing the system if the coolant is dirty or has been in the engine for a long time.

    ● Have a mechanic diagnose the issue: If you are unable to determine the source of the noise or if the noise persists after trying the above steps, it is best to have a mechanic diagnose the issue. They will have the tools and expertise to properly diagnose and fix any problems with your diesel engine.

Ben Michael

Ben Michael

Ben Michael, Director of Auto, Michael & Associates.

Top Off Your Oil

There are three kinds of unusual noises you'll hear from a diesel engine unless something truly catastrophic is wrong with it. Ticking noises come from one of three issues: oil levels that are too low, incorrectly adjusted valves, or knocking rods.

Your first step here should be to top off your oil. If the issue persists, you may have to take it in for service or have a look at the valves or rods yourself if you're handy.

A knocking noise almost always indicates a problem with injectors. If the knocking noise fades after the engine runs for a bit, it is probably just a case of the injectors needing some lubrication, but if the problem persists, it's time to look under the hood. Rattling noises have a few potential causes.

If the rattling mostly happens during acceleration, it's mostly a case of pre-ignition, where the fuel/air mix lights before it's supposed to. The most common cause of this is the wrong kind of fuel. A rattling noise that starts quite loud with a cold engine but gets quieter once things warm up could mean that you have a problem with your timing chain. You may simply need to tighten it, but if that doesn't work, you may need to replace it.

Kyle MacDonald

Kyle MacDonald

Kyle MacDonald, Director of Operations, Force by Mojio.

Check the Engine’s Oil Level

One of the most common noises heard from diesel engines is a knocking noise. This is likely due to your engine's oil level. If the oil level is too low, your valvetrain isn't going to be properly lubricated, which is what causes that knocking noise. It's a simple fix, but a very important one. Make sure your oil levels are adequate to avoid further damage to your engine.

Nick Valentino

Nick Valentino

Nick Valentino, VP of Market Operations of Bellhop.

Inspect Your Engine for Anything Unusual

If you're experiencing a noise coming from your diesel engine, the first thing to do is to give it a thorough once-over visually. Inspecting your engine for anything that looks out of place or damaged should be your first step in troubleshooting any unusual noises. If all appears normal, then next check your oil and air filters as well as other possible sources of noise like the exhaust system or pulley belts. Taking these precautions may help you determine the source of the sound before you take it in for professional service.

Jed Silverlake

Jed Silverlake

Jed Silverlake, Founder & Editor of MarriedHome.com.

First Find the Source of the Noise

If you're hearing a knocking noise, it could be caused by low oil pressure, an incorrect fuel mixture, or excessive carbon build-up on the pistons.

If you're hearing a clicking noise, it could be due to a loose belt, an electrical problem, or a dirty fuel injector.

If you're hearing a humming noise, it could be caused by a problem with the alternator, water pump, or power steering pump.

Once you've identified the source of the noise, you can start to troubleshoot the problem. If you're still having trouble finding the source of the noise, or if you can't fix the problem yourself, it's time to take your car to a mechanic or diesel specialist.

This is a crowdsourced article. Contributors' statements do not necessarily reflect the opinion of this website, other people, businesses, or other contributors.


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