What is EGR?
This topic should first start with the definition of EGR. Enough drivers do not know anything about this part, so it will not hurt to briefly explain what it is about.
EGR (exhaust gas recirculation) or AGR (Abgasrückführung) is a valve that regulates the amount of exhaust gas that will be returned for re-combustion. Like the DPF and EGR has a role to reduce environmental pollution. Unlike the DPF EGR is started to be implemented even on EURO 2 diesel engines and it is available in almost every turbo diesel after 1998. So EGR has a role to reduce pollution by making part of the exhaust gases back again to the combustion engine. At the beginning of the use of EGR valve was controlled mechanical vacuum suction branch. It was later replaced by a solenoid valve which controls the engine computer ECU.
When the car is brand new and EGR correct his work does not significantly affect the reduction in engine performance. But eventually the EGR gets dirty with soot from the exhaust and stops working properly. The engine has no power and often can not even work.
And when it works properly EGR does not work for the engine or performance. Actually doing the damage. Suffice it clear that when the engine instead of the cold fresh air rich in oxygen to the inlet gets polluted hot smoke, it does not contribute to improved performance. Over time manifold, cylinder head and around the valve deposited soot mixed with oil vapor, which only reduces the amount of air entering the engine.
EGR has a useful secondary role. And that is heating the coolant. When the temperature of the exhaust gas through the heater through which the coolant raise the temperature of the same. This does not mean that the engine without EGR will not be heated in such a situation, but the temperature of the somewhat slower to catch up. Timelines were compared the differences are slight.
How to solve the problem of EGR?
- Substituting for a new one. Quite expensive alternative.
- Purification of the old. Mostly short-term solution. Once it starts that the real problem that always returns.
- Physical closure. Mostly solves all problems except that the error P0404 repeating the diagnosis or the instrument panel for the newer models.
- The physical closure and software off. This is a permanent solution, error never occurs and the problem is permanently resolved.