The small problems you notice with your diesel engine today might signal bigger troubles ahead. A little extra shake or your engine taking longer than usual to start should not be ignored. These warning signs often lead to serious problems, from failing fuel systems to blocked diesel particulate filters.
You need to catch these common diesel engine problems early to avoid costly repairs. This applies to all diesel-powered equipment, including mining machines, farm equipment, trucks and 4×4s.
Common Diesel Engine Issues
Diesel engines are known for their durability, but they’re not without challenges. Common issues include excessive vibration, difficult cold starts, fuel injector failures and DPF (Diesel Particulate Filter) clogging, all of which can impact performance and efficiency.
The colour of your diesel engine’s exhaust smoke is a good indicator of its health:
- Black smoke usually means your air-to-fuel ratio is off, which happens with bad injectors or a clogged air filter.
- Blue smoke occurs when your engine burns oil. This is usually due to worn valve guides or piston damage.
You should also keep a watchful eye out for these tell-tale signs of engine trouble:
- Engine knocking often points to compression problems or fuel injector issues.
- If your engine struggles to start, especially in colder months, this could be from bad glow plugs or fuel delivery problems.
Your engine could lose power entirely due to :
- Plugged filters
- Fuel contamination
- Low compression
- Faulty turbocharger
Be sure to watch your oil consumption carefully. Engine age, heavy use and worn valve guides can all cause increased oil use. Head gasket failure ranks among the most serious problems to watch. Heat cycles and pressure in cylinders can break down the gasket over time. This leads to oil and coolant mixing.
Modern diesel engines face their own set of challenges with emission controls. EGR and DPF systems help meet emission standards but can become trouble spots that need regular maintenance.
Early Warning Signs You Shouldn’t Ignore
Strange noises from your engine are often a warning about developing problems:
- A knocking sound usually points to oil contamination or timing issues that are caused by worn bearings or piston damage.
Your engine can also tell you that something is wrong through changes in its performance:
- If the engine suddenly loses power, especially when you have heavy loads, This is a clear sign of cylinder compression problems or failing turbochargers.
- The rough idling you experience might point to faulty injectors or fuel pump problems that need quick attention.
Additional warning signs you should also watch out for include:
- Needing to add oil more often than usual—this can signal that the piston rings are worn or that there’s cylinder liner problems.
- The engine keeps running after you switch it off—this is known as “diesel runaway”.
- You feel unusual vibrations during operation—this can be caused by faulty injectors, poor fuel quality or timing issues.
Simple Checks That Save Money
To avoid pricey repairs in the future, your diesel engine needs regular maintenance checks.
The first step will be to replace your fuel filters every 15,000 to 30,000km. Modern diesel engines come with two fuel filters that need simultaneous changes to work their best.
Coolant negligence causes more than 40% of diesel engine maintenance problems. Your engine needs coolant level checks every two weeks. A coolant change every two years will help stop acid buildup, which can severely damage your radiator.
Here are key maintenance schedules you should follow to avoid expensive repairs:
- Oil changes every 5,000km with standard oil or 8,000km with synthetic oil
- Air filter replacement every 10,000 to 15,000km
- Fuel filter inspection every 16,000 to 24,000 km
Using quality fuel will protect your injectors from damage, which can be costly—replacements can run up to $300 per injector. For added protection against contaminants, consider installing a secondary 2-micron fuel filter to extend injector life and maintain engine performance.
Your turbocharger will last longer when you let the engine idle for a few minutes before shutdown. This simple step and regular water separator draining keep your engine running smoothly.
Keep Your Trucks and Machinery in Perfect Condition with KS Mobile Diesel!
Your diesel engine serves as a reliable workhorse. However, repair costs can skyrocket when the warning signs go unnoticed.
To ensure your machine is firing on all cylinders, you need the support of a dedicated maintenance provider.
KS Mobile Diesel is a Mobile Diesel Service that provides full maintenance for clients across South East Queensland. Our fully equipped mobile service trucks can come to you wherever you are and provide servicing, maintenance and repairs.
Get in touch with us if you’d like to find out more or want to discuss your engine’s maintenance needs or diesel truck servicing.