Diesel Services

Mobile Engine Diagnostics

Accurate diagnosis is the foundation of effective diesel repair. Without a proper understanding of the fault, there is a significant risk of replacing parts that are not defective, or addressing symptoms while the root cause remains active.

Our diagnostic process begins with a full OBD fault code read and live data capture from the engine management system. This is followed by a physical inspection of relevant components identified through the electronic data. We record all findings and provide you with a written report that details what we found, what we believe is causing the fault, and what we recommend.

What this typically covers:

• OBD-II and manufacturer-specific fault code reading
• Live sensor data analysis (MAP, MAF, EGT, rail pressure)
• Injector contribution and balance rate testing
• Boost pressure and turbocharger performance checks
• EGR valve position and response assessment
• DPF soot load and differential pressure reading

Emergency Call-Outs

An unexpected diesel breakdown — particularly in a commercial setting — can have real operational and financial consequences. Our emergency call-out service is intended to provide a practical, qualified response for situations where a vehicle has become inoperable.

We attend with a comprehensive mobile toolkit and diagnostic equipment. Depending on the nature of the fault, many roadside repairs can be completed on location. Where the fault requires workshop facilities or specialist equipment, we will carry out a thorough on-site assessment and advise you on the most appropriate course of action.

Common emergency issues we attend:

• Fuel system failures and injector faults
• Loss of power due to turbocharger or boost issues
• DPF blockage causing limp mode or engine shutdown
• Overheating and coolant system failures
• Glow plug faults causing non-start in cold conditions
• EGR valve sticking or failure

Routine Maintenance

Scheduled maintenance is the most cost-effective investment you can make in a diesel engine. Neglecting interval-based servicing has a well-documented relationship with accelerated component wear, increased fuel consumption, and higher repair costs over time.

We carry out mobile maintenance at a location convenient to you — whether that is at your home, business premises, or fleet depot. All work is carried out to manufacturer service intervals using appropriate-grade oils and filters for your specific engine.

Maintenance services include:

• Engine oil and filter replacement (all grades and specifications)
• Fuel filter replacement and priming
• Air filter inspection and replacement
• Coolant condition testing and top-up or replacement
• Drive belt and ancillary inspection
• Glow plug condition check and replacement
• Brake fluid condition and level check
• General underbonnet inspection and report

The Diesel Particulate Filter (DPF) is a device fitted in the exhaust system of modern diesel vehicles to capture soot particles and reduce particulate emissions. Under normal operating conditions, the DPF periodically regenerates — burning off accumulated soot at elevated temperatures during longer runs at higher speeds.

When a vehicle is predominantly used for short journeys or urban driving, the DPF may not reach the temperatures required for passive regeneration, leading to a gradual build-up of soot. Eventually, this results in a warning light, reduced performance, and in severe cases, engine limp mode or shutdown.

Our DPF service covers:

• DPF soot load and ash load reading via diagnostic equipment
• Forced active regeneration where appropriate
• Pressure differential testing across the DPF
• Assessment of upstream components affecting DPF health (EGT sensors, differential pressure sensors)
• Honest advice on DPF condition — whether cleaning, forced regen, or replacement is the appropriate recommendation

Injector & Fuel System

Fuel injectors are among the most mechanically and electronically precise components in a diesel engine. Over time, the spray nozzle orifices wear, the internal sealing degrades, and deposits form on the spray tip — all of which affect the quality and pattern of fuel atomisation.

Poor atomisation leads directly to incomplete combustion, which manifests as rough running, increased smoke, elevated exhaust temperatures, and reduced fuel economy. In high-pressure common rail systems, even small deviations in injector return rates can have a measurable effect on engine balance.

Fuel system services:

• Injector contribution and balance rate testing
• Return rate measurement for common rail injectors
• Injection timing analysis via diagnostic software
• High-pressure fuel pump assessment
• Fuel contamination and water content inspection
• Low-pressure fuel circuit checks (lift pump, filter, supply lines)

The turbocharger is central to diesel engine performance, enabling the combustion of more fuel by compressing the intake air charge. Turbocharger faults range from minor actuator issues to bearing failure, and the symptoms vary accordingly.

Oil contamination of the intake tract is often one of the first indicators of a turbo beginning to fail. Other early signs include a gradual loss of boost, increased turbo lag, and unusual noises under load. A comprehensive mobile assessment allows us to differentiate between a turbo issue and related problems such as boost leaks or VGT vane sticking.

Assessment covers:

• Live boost pressure monitoring and analysis
• VGT (Variable Geometry Turbo) actuator testing
• Wastegate operation where applicable
• Intake pipe and intercooler boost leak check
• Oil feed and drain condition assessment
• Bearing play check (shaft movement measurement)