There have been various VW Amarok DPF problems reported to us by readers over the past couple of years, and we encountered this for ourselves during a long-term test. While there hasn’t been an official recall, we understand Volkswagen is currently investigating it due to the high number of early failures.
What is the DPF?
The DPF (Diesel Particulate Filter) is a device that forms part of the exhaust system, and is designed to reduce the amount of particulate matter that is released from the tail pipe. It effectively acts as a ‘sieve’ that catches around 80% of the harmful soot that has exited the combustion chamber.
VW DPF regeneration
After a while, the amount of particulate matter caught on the DPF starts to build and the Amarok removes this by a process called ‘active regeneration’ (the Amarok’s new V6 engine is too big for passive regeneration).
When the Amarok’s engine control software recognises a DPF blockage greater than 10%, it injects extra fuel into the engine. When the fuel-rich exhaust gases pass-through the Diesel Oxidation Catalyst, they raise the temperature high enough for the soot to burn (diesel particulate matter burns at 600°C).
The problem is, active regeneration on the VW Amarok requires at least a quarter of a tank of fuel, and 10 to 15 minutes driving at over 2,200rpm consistently. During this time, you may notice increased fuel consumption, a slightly different sound from the engine and a burning smell.
VW DPF warning light
As the VW Amarok DPF blocks very quickly, the DPF warning light can be on for a very short time before limp mode kicks in. Once limp mode is activated, the blockage is greater than 50% and active regeneration is no longer possible; instead, a forced regeneration is required at the Volkswagen Van Centre or even a replacement. The cost is usually covered as part of the warranty if its your first time.
VW Amarok DPF problems – how to avoid
Those knocking around farm sites, building sites and the cities are bound to encounter these problems a lot more frequently than those clocking up motorway miles. If the DPF light does appear, head straight for an open road and down gear to keep the revs high, which in turn will increase the temperature of the exhaust gases and burn off the trapped soot.