When to Service a Diesel Engine: Everything You Need to Know
If you drive a diesel—whether it’s a ute, 4WD, or commercial fleet vehicle—staying on top of servicing is one of the smartest things you can do. Diesel engines are renowned for their durability, but they still require regular maintenance to perform optimally.
At Core Diesel, we’re often asked: “How often should I service my diesel?” or “When to service a diesel engine?” The answer depends on a few key factors. In this blog, we’ll break it all down so you know exactly when—and why—to book in.
Key Takeaways
- Most diesel engines should be serviced every 10,000 to 15,000 kilometres.
- Your driving habits, environment, and engine age can affect this.
- Delaying service can lead to poor fuel economy and costly repairs.
- Core Diesel provides expert diagnostics and tailored diesel servicing.
Recommended Diesel Service Intervals
As a general rule:
- Service your diesel every 10,000–15,000 km, or at least once a year, whichever comes first.
This interval keeps your oil fresh, filters clean, and fuel system in check. However, different vehicles have different manufacturer guidelines. Some newer diesels allow longer intervals, but these recommendations assume ideal driving conditions, which most Aussie drivers don’t get.
What Affects How Often You Should Service Your Diesel?
Your engine doesn’t just run on fuel—it runs on how you drive it.
Here’s what can increase your servicing needs:
- Heavy towing (e.g. caravans, trailers, or tool-loaded trays)
- Off-road or dusty environments
- Short trips or stop-start city driving
- Extreme weather (hot summers or cold winters)
- High kilometres or older vehicles
If any of these apply to you, it’s best to err on the side of caution and get your diesel looked at more frequently.
🚨 Signs Your Diesel Needs a Service
Sometimes, your vehicle will let you know when it needs help. Look out for:
- Reduced fuel efficiency
- Sluggish acceleration or power loss
- Excessive smoke from the exhaust
- Rough idle or engine knocking
- Dashboard warning lights
If you’re experiencing any of these symptoms, don’t wait—get it checked before it develops into a major and expensive issue.
What’s Included in a Diesel Service?
At Core Diesel, our services are tailored specifically for diesel engines. A standard diesel service might include:
- Engine oil and filter replacement
- Fuel filter and air filter check or replacement
- Battery, belts, and hoses inspection
- Coolant level and condition check
- Scan for fault codes (diagnostics)
- DPF and EGR system inspection (if applicable)
- Test drive to confirm performance
We also offer detailed logbook servicing and preventative maintenance plans for commercial and fleet vehicles.
Logbook vs Preventative Servicing
Following your logbook is a great start—but it’s not the whole picture. Logbook intervals assume:
- Optimal driving conditions
- Clean fuel and air
- No towing or off-road use
In reality, most Australian diesel drivers require preventative servicing to avoid blocked DPFS, injector faults, and turbo issues. At Core Diesel, we adapt our approach to match how you use your vehicle.
Why Trust Core Diesel?
We’re not just a general workshop—we’re diesel specialists.
- Advanced diagnostics for modern diesel engines
- Experience across 4WDs, work utes, and fleet vehicles
- Tailored servicing to match real-world conditions
- Transparent, practical advice—no upselling
Whether you’re managing one vehicle or a whole fleet, our team is here to keep your diesel running reliably.
Frequently Asked Questions
How often should I service a diesel engine?
Every 10,000–15,000 km, or approximately every 6–12 months, depending on usage. More often for heavy-duty or harsh conditions.
What happens if I skip a service?
You risk oil sludge, clogged filters, injector damage, and reduced performance, which can lead to expensive repairs.
Can I service a diesel engine myself?
Basic checks are sufficient, but today’s diesels require diagnostics and expert handling, especially when DPFS and EGR systems are involved.
Do new diesel engines need less servicing?
Not necessarily. Some newer diesels run hotter and have more emissions tech, which benefits from more frequent checks.
Ready to Book Your Next Diesel Service?
Regular servicing is the key to avoiding breakdowns, improving fuel efficiency, and keeping your engine running smoothly.
Book your next diesel service with Core Diesel today and experience expert care from the team that understands diesel inside and out.
