Do you want to find out what an EGR valve is and what potential defects there may be in this part? Find out specific information about the exhaust gas recirculation and valve inside our articles.
Nowadays, EGR valves are a component of the exhaust system of all vehicle manufacturers. The Valve and the EGR cooler are normally located near the engine block.
The main function of this part is to regulate the exhaust gases that enter the intake tract and after that the combustion chamber (EGR flow rate). In most vehicles, the location of this part is close to the intake manifold or directly in the EGR-cooler, if available. Compared to gasoline engines, the opening cross-section of the valve is usually smaller than in diesel engines. This is because the EGR rate in diesel engines is much higher than in gasoline vehicles.
There are two different types for the function. On the one hand, there are pneumatic EGR valves that are actuated via an electromagnetic valve using a vacuum. On the other hand, there are EGR valves that are controlled directly by the engine control unit (electrically).
The valve is a small component in the engine compartment, which may be difficult to find on the first view.
This part is equipped with an inlet and an outlet for the exhaust gases. In addition, depending on the control option, either a vacuum box is installed or an electric motor.
Bad/faulty EGR valve symptoms
In most cases, a defect in the EGR system is related to an faulty EGR valve.
Over time, the soot particles inside the exhaust emissions settle on the valve and on the cooler. Sooner or later they penetrate the mechanics of the parts. This can cause the EGR valve no longer being able to open or close properly. In the worst case, the EGR valve can get stuck in one position.
This means that the calculated air mass from the control unit does not reach the combustion chamber. Thus, no clean combustion can take place.
These problems with the egr valve may occur while driving:
- Illumination of the check engine light
- Decreased engine power
- Engine jerking
- Bad fuel economy
- Rough idle
- Strong soot formation from the exhaust during acceleration
- Fault code entry for EGR valve such as ‘EGR valve rate incorrect’ or similiar
Is it possible to continue driving with a defect on the EGR valve?
Whether you can continue driving if the EGR valve is defective depends on what type of defect is present.
If the valve is in the closed position, you can continue to drive the vehicle. However, if the valve is stuck in the open position, it is usually not possible to continue driving the vehicle because the engine will run poorly or not at all.
However, you should keep in mind that the EGR system plays an important role in meeting the increasing requirements of the emission regulations. For this reason, it is strictly forbidden in most countries to disable or remove the EGR system. In addition, you may be subject to heavy fines if you are stopped with a defective exhaust gas recirculation valve.
Importance of an EGR valve
The EGR system is a system in modern cars that is important to meet increasing exhaust gas requirements.
Considering a purely technical point of view, an engine may also run without this system installed without any problems.
The removal of this system may also lead to increased engine performance. Furthermore, the removal of the EGR may prevent contamination of the engine, especially of the intake manifold.
But be aware, of course, the EGR system is installed inside the engine for a reason. The EGR valve has a major contribution to meeting the increasing exhaust gas regulations requirements. For this reason, it is strictly illegal in most countries to shut down or remove this system. If this system is removed without further adjustments, the vehicle will not run as usual either. Of course, the check engine light will also come on while driving.
How much is an egr valve replacement?
The costs of repairing an issue on your EGR system always depends on the specific reason for the defect. In most cases, the EGR valve itself is defective, which can cost between US$ 100 and US$ 500. The cost range specifically depends on whether the component is changed in a workshop or by yourself.
Cleaning EGR valve: Tips and tricks for effective cleaning
The valve does not always have to be replaced immediately if it is indicated as defective in the fault memory. In many cases, it is sufficient to remove the EGR valve and clean it thoroughly to restore its function.
To achieve the best possible cleaning effect, the valve should be removed. In addition, there are special cleaners that can also clean the EGR valve of stubborn coking and dirt.
After the valve has been reinstalled, the fault memory should be deleted and a test drive carried out again.
Diagnosis and repair of EGR valve faults
If you suspect any issue, we recommend running a diagnosis using an OBD2 adapter, first. This will read your error memory from your ECUs. In many cases you can find out when an error (DTC) has been detected and what specifically the error is.
OBD adapters and diagnostic equipment can be used to diagnose a variety of engine problems, regardless of make or model. The issues found vary between simple sensor defects and more complex problems, such as turbocharger defects. In some specific cases, an OBD adapter can help already fixing an issue. Sometimes just clearing old trouble codes (DTCs) will help, saving you a trip to the repair shop.
Whether you like fixing stuff yourself or you are a professional, a diagnostic device is a valuable tool that every driver should have in his car.