Common Diesel Problems:
What We See Every Week
At Core Diesel in Maryborough we work on diesel 4WDs, utes, trucks, and heavy machinery every day. These are the problems we see most often, what causes them, and what the fix actually involves. Find out what might be affecting your diesel.
DPF Cleaning
Most common diesel problem #1
DPF Blockage
What it is
Your DPF captures soot from combustion and burns it off during highway driving. Short trips and stop-start conditions prevent that burn-off and the filter gradually blocks.
What you notice
DPF warning light, reduced power, engine going into limp mode, increased fuel consumption, or excess smoke from the exhaust.
What we do
We use the Hydro DCS-20 Pro to clean blocked DPFs without cutting or replacing them. Pre and post flow testing on every job.
Carbon Cleaning
Most common diesel problem #2
Carbon Build-Up
What it is
Soot from combustion accumulates in the intake manifold, EGR valve, injectors, and combustion chamber. Worse in diesels doing short trips or city driving.
What you notice
Rough idling, sluggish acceleration, poor fuel economy, excess smoke, or repeated EGR fault codes on a diagnostic scan.
What we do
Professional carbon cleaning using hydrogen-based induction systems and chemical treatments. We diagnose first to confirm carbon is the cause.
Turbo Diagnostics
Most common diesel problem #3
Turbocharger Failure
What it is
The turbo compresses air into your engine to increase power. It runs at extreme speeds on clean oil. Wear, oil quality issues, or overheating all cause failure.
What you notice
Loss of power especially under load, blue or black smoke, a whining or screeching noise from the engine bay, or limp mode activation.
What we do
Boost pressure testing under load, fault code scanning, inspection for oil leaks and shaft play, and dyno testing where needed. Many cases are repairable.
Suspension Upgrades
Most common diesel problem #4
Suspension Wear
What it is
Shocks, springs, bushings, and ball joints wear over time, particularly on 4WDs used off-road, towing, or carrying heavy loads. Factory setups are not built for Australian conditions.
What you notice
Excessive body roll, rough or bouncy ride, uneven tyre wear, vague steering, or a vehicle that sags at the rear when loaded.
What we do
We match the right kit to how you use the vehicle. We supply and fit Outback Armour, Dobinsons, EFS, OME, Bilstein, and Tough Dog for all major platforms.
EGR Cleaning
Most common diesel problem #5
EGR Valve Problems
What it is
The EGR valve reduces emissions by recirculating exhaust gas back into the engine. Carbon deposits cause it to stick open or closed, disrupting performance.
What you notice
Rough idling, black smoke, poor fuel economy, a strong smell of fuel, or an EGR-related fault code on a diagnostic scan.
What we do
EGR cleaning as part of our diesel emissions service. We advise honestly on repair vs replacement before any work begins.
DPF Diagnostics
Most common diesel problem #6
Failed DPF Regeneration
What it is
When a DPF reaches a certain blockage level your vehicle attempts an automatic regen. If the filter is too blocked or the drive cycle too short, the regen fails and the problem compounds.
What you notice
The DPF light comes on, may clear briefly, then returns. The engine may idle roughly or enter limp mode if the cycle repeats without clearing.
What we do
A diagnostic scan confirms whether a regen attempt failed and tells us how blocked the filter is. We then recommend the right cleaning approach or a forced regen under controlled conditions.
Not sure what is wrong with your diesel?
A diagnostic scan takes the guesswork out. We will tell you exactly what is going on before any work begins. Based in Maryborough, servicing Maryborough, Hervey Bay, Bundaberg, and the wider Fraser Coast.