EGR/ exhaust gas recirculation
The exhaust gas recirculation system (EGR) feeds exhaust gases back into the engine through the intake and due to lack of oxygen, this reduces NOx in internal combustion engines.
The system is subjected to very high loads. This can cause problems especially in vehicles that are driven a lot at part load. In partial load, much exhaust gas is returned, especially in diesel engines, application increases soot emissions due to lack of oxygen during combustion. The return of this air causes the intake in many engines to clog up with soot.
When an engine is new and has no internal contamination yet, it is a perfect system, however, when the intake clogs up so much or the valve no longer closes properly, consumption increases and power decreases. The air-fuel ratio continues to deteriorate and lose efficiency/the engine suffocates as it were. Then, to achieve the same acceleration, one imperceptibly depresses the accelerator pedal further and intake fouling also increases faster.
Low revs and short trips are especially taxing, the ANWB gives about 100,000km as the lifespan for an egr valve. From experience we find that EGR problems are often between 50,000km and 200,000km depending on brand model and use, it is common that the EGR does not yet cause a malfunction in the engine management but already problems due to contamination or malfunctioning EGR have occurred. Continuing to drive with a broken EGR causes many consequential problems and is not advisable.
- Soot filter fills up at an accelerated rate
- The engine delivers less power
- Consumption increases
- Engine may even stutter
- Error message with readout or malfunction light on dashboard.
- Uneven engine power.
- Replace EGR with a new system and possibly clean intake, with many car brands this can be quite pricey technically due to parts price and labor hours for replacement.
- Close EGR, leave the egr permanently closed by software modification, in some cases it is necessary to also close mechanically by a blind plate/egr plate. note! shutting down the EGR should be seen as a temporary emergency solution. Deactivating the EGR causes the car to no longer meet the issued Euro standard and type approval.
- EGR cleaning, de/mounting egr valve and cleaning in special bath or blasting this process is very labor intensive.