A faulty DPF can damage the turbocharger

Yes, unfortunately, this is true. A clogged, faulty DPF / FAP or catalytic converter is a nightmare for your turbo. The situation can also be reversed and it is a faulty turbo that will lead to a clogged particulate filter.

Malfunction of one component will lead to problems with another. A vicious circle is formed. A clogged particulate filter causes a significant increase in the mechanical load of the turbocharger. Problems with DPF are often accompanied by dilution of engine oil with fuel and the turbocharger requires good lubrication of elements. An engine with a damaged turbocharger emits more soot, which clogs the gaps in the particulate filter monolith.

Nowadays when the fashion for downsizing and being eco-friendly has taken over the automotive world it is more and more difficult to find units without turbocharging or complicated exhaust gas filtering systems. Diesel without DPF/FAP/SRC, or naturally aspirated diesel engines are becoming obsolete. As it often happens – additional components may generate additional difficulties and unexpected costs. Durability of turbochargers and particulate filter is interrelated. A malfunction of one of the components will sooner or later cause a failure of the other.

Properly working DPF/FAP catches up to 90% of particles, which results in its rapid filling up. To avoid frequent replacement, the system must allow for regeneration of the device. In order to burn out the soot it is necessary to increase the temperature inside the monolith, for example by additional injection of fuel, or must be applied a special substance (cerium oxide) reducing the degree of heating of the filter necessary to eliminate the carbon. Unfortunately, even such self-cleaning process is not one hundred percent effective. Inside the cartridge, there is still ash which has not been burnt. As a result of its storage eventually comes to clogging of the DPF. It also happens that active regeneration is not carried out well – it is simply interrupted, or by various factors does not start at all. Then the amount of sediment increases and reduces the capacity of the filter.

During active regeneration a dose of fuel is supplied to the filter to help it warm up. If the process is interrupted, the unburned fuel will flow into the engine oil increasing its volume and decreasing its density. Therefore, in some cases (especially in city cars) you may notice an increase in the oil level. It is then necessary to immediately change it and go to the diagnostics to determine the cause of the situation. An increase in backpressure is a deadly factor for the turbocharger. It occurs when the DPF becomes completely clogged and exhaust gases cannot pass through it into the exhaust.

Effects: – violation of the turbine seals by the gases – blowing out oil from the rotor shaft bearings, charring of its residue – deterioration of lubrication – mechanical damage inside the turbine (blades, bearings, shaft).

How to avoid failures? First of all, eliminate the first symptoms of DPD/FAP obstruction, make sure that the automatic regeneration process of the particulate filter runs properly and is not interrupted. Do not underestimate the glowing lights, messages popping up on the onboard computer. You can not delay with solving this type of problem. You need to act quickly so that this fault does not lead to further.