Recently did a DPF EGR delete and remap on a a great condition 325d E91.
We get a lot of questions about EGR Deletes, we always inform customers that you cannot delete an egr without deleting the dpf. Anyone that suggests otherwise is misinformed. If you delete an EGR valve with a DPF present then you will block the DPF as the two systems are linked. If you’ve had just an EGR deleted elsewhere then be warned the DPF will block.
Good old m57 engine.
The EGR Valve is used to lower the emissions at idle. The idea being that if you reduce the amount of oxygen entering the engine then you can reduce the temperature in the combustion cylinder and thus reduce emissions.
The valve works by recirculating some of the exhaust gases back into the engine through the air intake system, reducing the amount of emissions that exit the car. The problem lies with the exhaust fumes that contain carbon deposits, these fumes are constantly being recirculated through the engine which over time will cause a build-up of the carbon deposits in the intake manifold and other in other parts including the EGR valve. This build up in the valve is often what causes them to fail. Not to mention it will reduce performance within 50,000 miles as everything will get covered in carbon. You will reduce the amount of air that can flow as everything gets blocked and covered in thick coke.
A typical BMW EGR valve covered in carbon below:
Everything in the inlet manifold including the valves will also be covered in this carbon.
Benefits of removing the EGR Valve
- Lowered Engine Temps
- Improved Throttle Response
- Improved Economy
- Reduces Oil Contamination
- Reduces Carbon Deposits in the engine