Diesel Particulate Filter (DPF)
What is a DPF and How Does It Work?
Most Mercedes Sprinter and Vito Vans are fitted with Diesel Particulate Filters (DPF) in the exhaust. DPF filters are designed to capture black carbon from the exhaust gases in order to reduce pollution. Once the DPF filter reaches a specified fill level, the Engine Control Unit (ECU) will initiate a Regeneration Burn. This is an automatic process which occurs every 400 to 800km and causes the exhaust temperature to increase above 500 degrees celsius! The increase in exhaust temperature during regeneration is caused by deliberate late and excess fuel injection by the ECU.
In a Mercedes Vito or Sprinter, there will be no dash lights, noises or smells during the regeneration process and the driver can continue their journey as normal. It’s designed to be a seamless process.
What does a DPF look like?
The filters resemble a metal exhaust muffler from the outside, with multiple pressure and temperature sensors plumbed in. The internal element resembles a metallic sponge or honeycomb structure, which allows exhaust gases to pass through whilst capturing the carbon. The metallic structure inside is coated with platinum and other rare metal catalysts which mean the DPFs are costly to manufacture.
Does My Sprinter or Vito Have A DPF?
In Australia, DPFs are fitted to 906 series Sprinters from 2006-Onwards (not 903 or 904 series). Vitos first had DPFs fitted in approximately 2007 to the 639 series chassis. All models of Mercedes Vans thereafter are fitted with DPFs.
What Maintenance Does My DPF Require?
The good news is that, unlike other brands, Mercedes DPF systems are very well designed. Most owners will see 500,000km+ before their DPF needs replacement due to Ash buildup. The only maintenance requirement is that low ash (Low SAPS) engine oil is used. Our Mercedes MB229.52 specification engine oil ensures that this requirement is met.
Symptoms of a DPF Problem
As the DPF becomes overfilled, it will block the exhaust flow. You may notice:
- Reduced performance
- Limp Mode
- Engine Light On
- Bad Exhaust Smells
- Increased Fuel Consumption
Why Have I got a DPF problem?
The automatic regeneration process sometimes fails to occur. This can be for dozens of reasons. The most common reasons are:
- Engine Light is on
- Engine fault codes are present
- Low turbocharger boost or leaks
- Exhaust temperature is too low
- Fuel level is too low
The root cause of the problem is rarely the DPF itself, rather it is usually an electrical or mechanical issue that prevents DPF regeneration.
Note that if a Sprinter or Vito is driven for an extended period whilst the DPF is overfilled/blocked or with the engine light on, the DPF may in fact be damaged. Thus it is very important to have engine light, limp mode or performance issues diagnosed and repaired promptly.
Repairing DPF Systems
At Eurostar Diesels we are very experienced at fixing DPF problems and more importantly, finding the root cause of the DPF problem, which can often be; engine sensor problems, turbo boost air leaks, fuel pressure faults etc.
Once the cause is diagnosed and repaired, the DPF can usually be cleaned by initiating a manual/forced regeneration. This is done using our Mercedes diagnostic PCs. We see a 80% success rate with manual or forced regenerations.
If a manual DPF regeneration is not successful, the DPF can be removed and cleaned in a liquid bath solution. This is a better although more time consuming method. It is more successful in removing tough carbon and ash deposits from within the DPF filter.
Get in touch with us today to discuss your DPF needs via our booking form, chat or phone. We’re always happy to offer advice!
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