Get up to speed on the latest technology for diesel particulate filters and diesel exhaust fluid with Car Service Windsor Gardens.

Most diesel engines that are sold nowadays are fitted with a diesel particulate filter, and many of them are using Selective Catalyst Reduction, commonly referred to as Diesel Exhaust Fluid or AdBlue. You can verify this by looking up the vehicle details. There are many benefits to driving a diesel engine, but they are very different to your petrol internal combution engine.

Should the driver’s typical driving habits fail to meet the requirements for a regeneration to take place, and the soot levels begin to climb to an unacceptable level, the yellow warning light will light up. This is not an error; it is meant to tell the driver that a manual regeneration must take place and that the driving process detailed in the owner's manual should be followed as soon as possible. It has been found that if the driver utilises the cruise control where it is safe to do so, it tends to quicken the process. This isn't stated in the owner's manual, but it seems to help.

If the driver fails to do so and the light changes to red, the DPF may not be able to be restored. The driver may be asked to cover any time and labour involved with carrying out a forced regeneration, or even for the replacement of the DPF (estimated cost of about $5,000). Technicians can see via the diagnostic machines if the driver is not engaging in regenerations when they should, or if their typical driving practices don't allow for passive regeneration.

Throughout the passive regeneration process, the start/stop feature will be disabled to prevent interruption, and the engine may operate differently with a distinctive smell from the exhaust which is normal given the high temperatures within the DPF.

The type of driving undertaken has a major influence on the performance of the DPF. If the driver frequently makes short trips where the engine fails to reach its full operating temperature, they will most likely experience issues with their DPF as the regeneration won't be completed unless specific criteria of engine temperature and running time are satisfied. In addition, switching off the engine during the regeneration process will quickly elevate the soot levels in the DPF to an unallowable level and activate the yellow warning light. We have seen examples of this happening in under 350 km of driving. Even if a driver takes long drives every so often, but primarily drives in short distances, they are not exempt from DPF problems. The car will only carry out a regeneration when necessary and won't do so if the soot level does not reach the predetermined threshold.

Two additional driver actions can terminate a regeneration; one is driving with both feet, in which case the regeneration will be aborted if the car perceives a simultaneous brake and accelerator input. The other is rapid acceleration and braking, as the increased engine temperature during the regeneration process has the capacity to trigger an overheating, thus the regeneration will be terminated.

AdBlue is the commonly known name for Diesel Exhaust Fluid (DEF). A number of our brands utilise DEF, so we need to be informed about this technology and how it can affect our customers. At present, Bentley, Maserati, Audi, Volkswagen Passenger and Commercial, Jaguar, and Land Rover all make use of DEF.

DEF is added to the exhaust in an exact measure and consumption can change depending on the vehicle’s driving pattern. We’ve noticed that cars that do longer, faster trips utilize less DEF than those driven in urban areas. Due to the changing levels of use due to driving habits, it’s challenging to advise a customer on how often they must refill the DEF, with an average of approximately every 8,000 km - some less, some more.

The vehicles have a countdown system based on mileage that offers the client enough warning to refill it. The alert signals differ between cars, but the DEF low light is just an indicator that the driver needs to refill it, when possible, no different from the low fuel warning light. If the DEF warnings are disregarded, starting will eventually be hindered and the car must be towed to avoid any damage to the system and keep the car within its legal emissions levels.

DEF can be acquired from the Service Department, either through the parts department or from the workshops that keep larger amounts of it and can refill the tank for the customer. DEF has a shelf life of 12 months and the vehicles can detect its quality, using expired fluid could create a problem and the car would need to visit the workshop.

If the car is on a Service Plan (Audi and JLR), the refills are included and cost nothing to the customer. For Volkswagen, the average refill is around $30 and the top-ups take around half an hour.

Customers must be careful when refilling their DEF tank themselves, as an overflow could log fault codes and require a visit to the workshop to adjust the level and reset the car. It is therefore suggested to add a limited amount (5-8L) of DEF to the tank to ensure a smooth journey without the risk of overfilling. If DEF is put into the fuel tank (a potential hazard with some cars that have their fuel filler near the DEF fill point) there is a substantial danger of damaging the fuel system, which can cost thousands of dollars to fix - in some cases, the entire fuel system has to be replaced.

If you have any further questions about your diesel engine, you can come in and speak with our specialists at our Windsor Gardens workshop.