Many workshops and wholesalers have gradually become acquainted with the frequently used EGR-valve that applies to diesel engines of the types 1.4, 1.6, 1.9 and 2.0 TDIs. Despite several attempts, VAG or other aftermarket actors have not succeeded in solving the problem. Based on our own technical studies, we in this article unveil why the EGR valve stops working too quickly.
The fundamental cause of the EGR valve problem with the latest OE number. 03L131512DQ is inconveniences in its design and selection of components in and around the valve itself and its control mechanism. The design allows exhaust gas to penetrate parts of the valve's mechanical and electronic control.
Triscan EGR valve 8813 29102 / VAG OE-no. 03L131512DQ
When the EGR valve is closed and does not lead exhaust gas into the intake manifold, pressure is built on the back of the valve (the side of the valve where the exhaust gas supply takes place). The tolerance between the valve and the valve control sleeve results in the exhaust gas being directed into the adjacent chamber (see illustration A, item 1).
Illustration A Illustration B
In the chamber, where the gas has found its way to, the valve control is connected to the control mechanism valve positioning hook (see illustration B, item 1). The valve positioning is controlled by rotating the hook by means of an electric motor and the two components are connected to each other via an axle. The hook and the electronics for controlling the electric motor are located in separate compartments (see illustration A, item 2 and 3). The exhaust gas utilizes the shaft seal and the needle bearing to find its way from one chamber to another.
The image clearly shows how the exhaust gas has penetrated and melanised the chamber and the parts included in the valve control mechanism
The penetrating exhaust gas has several negative impacts, which over time will lead the EGR-valve not to work properly or to fail.
1. The needle bearing is soiled with soot, which means that the function of the bearing is reduced.
2. Condensation is formed, which means that the needle bearing begins to corrode. Over time, the function of the bearing reduces and eventually fails completely.
3. For the electric motor, the consequences of a defective needle bearing are that the electric motor is unable to rotate the shaft and thereby activate the valve.
4. And for the electric circuit the soot formation can over time cause the electric circuit to fail.
The image clearly shows how the exhaust gas has penetrated and the circuit board and its components are soiled with soot
VAG software update after the dieselgate scandal also has an influence on the EGR valve
Many of the cars equipped with this type of EGR valve are part of the dieselgate scandal. VAG has offered the owners a software update for the engine control which should solve the emission-related issues, especially nitrogen oxides (NOx). It is therefore also important to mention that a software update has a major impact on the EGR valve. After an update, the EGR valve will be activated much more often and thus be subjected to a much larger wear.
As mentioned – and for the time being – there is no solution to the problem, we can only explain why it's going wrong. As a workshop or wholesaler, it is important to know the background and to be able to explain the problem. It doesn’t matter to what garage the car owner will take the car to get it fixed – the problem is the same – also at a VAG-certified garage. At Triscan we keep up to date with the latest development, have a close dialogue with our manufacturers and will disclose any relevant information as soon as news is released.