Frequently Asked Questions

Frequently Asked Questions

1. What are DPF’s?

A Diesel Particulate Filter (DPF) is an integral filter in a diesel vehicle’s exhaust system that captures and traps potentially hazardous soot particles and build up. All modern diesel vehicles from 2006 onwards come with a DPF, this is designed to ensure harmful chemical substances are not being released into the atmosphere.

2. Why do we need to clean a DPF

Over time, the DPF begins to build up with soot. There are a number of contributing factors as to why DPF’s clog up. These include:

  • Quality of Fuel – using Bio Fuels can contribute to extra soot build-up as Bio Fuel may not burn as clean as regular diesel fuel.
  • Quality of Engine Oil – using incorrect oil specified for your engine can significantly add to the amount of soot build-up in your DPF
  • Temperature– Filter regeneration requires the temperature of a DPF filter to be around 600c. These temperatures will only be reached at high speed, long trips. Therefore, low speed driving will not reach high enough temperatures, causing the filter to block faster
  • Style of Driving – Diesel engines are not designed for short journeys and low-speed driving. Therefore, inner city driving can cause a faster build-up of soot as the regeneration process is less likely to occur.
  • Year Model/High Kilometre Vehicles– as a vehicle with DPF systems age and begins to wear out, filter regeneration becomes harder to complete

3. How often does a DPF need to be cleaned?

The frequency between each DPF clean will vary based on whether your vehicle coincides with the variety of factors as outlined in question 2. Furthermore, the frequency of your DPF clean will vary by manufacturer and level of vehicle usage.

4. Will the DPF last as long after it has been cleaned?

Getting your DPF regularly cleaned will guarantee many more kilometres and years of service on your vehicle and filter, restore engine performance and increase fuel efficiency. Getting your DPF back to its original condition is based upon a number of contributing factors, including the vehicles previous service history and overall care of the vehicle by its owner etc.

5. DPF Cleaning Additives – What are they and do they fix the problem?

DPF cleaning additives are chemical solutions that claim they will adequately clean a DPF without the need to remove and clean the DPF professionally. DPF cleaning additives are only a temporary fix and a band-aid solution. The only true way of cleaning a DPF, especially for city drivers, is to get it professionally removed, cleaned and serviced.

7. What are EGR’s?

EGR is a nitrogen oxide (NOx) emissions reduction process used in petrol/diesel engines. EGR works by recirculating a portion of the engines exhaust gases back to the engine’s cylinders. The EGR reduces the NOx by lowering the oxygen concentration in the combustion chamber as well as through heat absorption.

8. Symptoms of a failing EGR?

Symptoms of a bad or failing EGR include engine performance issues like decreased power and acceleration, rough idle, and the Check Engine light on the dash.

9. What are SCR’s?

Selective Catalytic Reduction (SCR) catalyst converts harmful and hazardous gases (NOx emissions) into harmless nitrogen gas and water vapour. The SCR catalyst system is a reliable technology that enables enhanced fuel economy, requiring very little maintenance.

10. What are DOC’s?

Diesel Oxidation Catalyst (DOC) is a device designed to oxidize carbon monoxide in the DPF. DOC increases passive regeneration – an ongoing chemical process to oxidize carbon during a vehicle’s regular operation, also known as ‘self-cleaning’.

11. What are CAT’s?

A Catalytic Converter (CAT) is a device in the exhaust system that converts and breaks down toxic gases and substances from an internal combustion engine to less toxic pollutants by catalysing a redox reaction.

12. What are the symptoms of a failing CAT?

  • Your vehicle’s fuel efficiency drops suddenly
  • Your vehicle loses power and doesn’t accelerate
  • Your vehicle fails an emissions test
  • Strong exhaust odours
  • Your engine light comes on

13. Does the DPF cleaning come with a warranty?

As we have no control over how the DPF is maintained no filter is warranted. What we do is guarantee that the DPF is returned to you in a near new condition.

14. Do you supply aftermarket DPF?


15. What is an intercooler?

An intercooler is an intake air cooling device commonly used on turbocharged and supercharged engines. An intercooler cools the air compressed by the turbo/supercharger, reducing its temperature and thereby increasing the density of the air supplied to the engine.

16. Should I clean my intercooler?

Yes. One of the biggest problems with intercoolers is excessive build up of engine oil internally. Oil becomes trapped inside the cooling tubes restricting the airflow, this reduces the ability of the turbo to boost pressure effectively. If not cleaned and a blockage occurs it can cause the intercooler to fail and cause further damage.

17. What is a radiator?

The radiator transfers the heat produced by the engine block from the fluid inside to the air outside, thereby cooling the fluid, which in turn cools the engine. A cooling system works by sending a liquid coolant through passages in the engine block and heads. As the coolant flows through these passages, it picks up heat from the engine. The heated fluid then makes its way through a rubber hose to the radiator in the front of the car. As it flows through the thin tubes in the radiator, the hot liquid is cooled by the air stream entering the engine compartment from the grill in front of the car. Once the fluid is cooled, it returns to the engine to absorb more heat. The water pump has the job of keeping the fluid moving through this system of plumbing and hidden passages.

18. Should I clean my radiator?

Yes. If your engine is overheating it could be due to a dirty radiator. Coolant flushes are a must as this prevents corrosion but does not remove the dirt and sludge that gets stuck to the inner channels. This accumulation reduces of the flow of coolant which causes overheating. The Flash Cleaner will give the radiator a new lease on life.