- EGR recirculates exhaust gases to reduce NOx emissions.
- EGR valves fail often, harming performance and raising maintenance costs.
- Carbon buildup and heat cause wear; replacements can be costly.
- Common signs include the check engine light or valve stuck open/closed.
Usually, all the modern cars we see on the roads are equipped with an EGR system, the valve that refers to the recirculation of exhaust gases. Whether you own a petrol car or a diesel one, it will have an EGR valve, although the principle of operation differs.
The exhaust system of a car is equipped with an EGR valve, which due to the fact that it is not properly maintained, comes off quite easily, and for this reason, the car has a much poorer performance.
Well, in the rest of this article you will be able to find out a lot of very important information that can be very useful for you to find out what are the symptoms that betray EGR valve problems. This way you will find out when the EGR valve is damaged, and you will know how to fix the problem.
Unfortunately, EGR valves fail quite often, and the worst part is that replacing them can cause a deep hole in your budget. It is necessary that these EGR valves be able to withstand a high degree of wear, which can be caused by both hot air and the carbon that accumulates inside them (coming from inside the cylinders, carbon that appears as a side effect of combustion).
You will probably want to gather more information about these EGR valves, to know if they can be replaced at home, or if you need to drive to the service, but in the following you will find out more details.
What is an EGR valve?
Exhaust gas recirculation is a self-explanatory term, but in terms of applying this term, things are not as simple as it seems. The EGR recirculates the exhaust gas back to the intake manifold for later use in terms of combustion.
In this way, a reduction of NOx emissions is obtained first of all and the car will pollute the air and the environment much less.
But the EGR system comes not only with advantages, but also with disadvantages, and one of them is related to fuel consumption, which will increase significantly, while diesel cars will have lower performance and soot production will be higher. great due to the EGR system.
Despite these disadvantages, the newest cars have intelligent technologies that are very efficient, and here we can discuss new diesel cars, which currently have an EGR cooler, and its role is to cool the exhaust. using engine coolant.
How to detect a bad EGR
Given the fact that the EGR system acts on the exhaust gases, and here we mention for example NOx and carbon dioxide, there are high chances that this system will deteriorate a lot over time.
If you are wondering what this means, well, the result may be a reduction in car performance, but also an increase in pollution.
When the EGR valve is bad, it is normally necessary to turn on the EPC lamp (in the case of VW cars), or the engine check light, Check-Engine.
Regarding EGR valves, it is important to mention that they have two main aspects, so they either remain open or close completely when they fail.
Next, you will find out how you can spot some clear signs that an EGR valve is bad.
1. Check if the on-board indicator light comes on (EPC or Check-Engine)
If the car’s on-board computer encounters any problems with the EGR system, it will activate the engine test lamps.
It is necessary to be aware that these lamps can light up for other reasons, but to know exactly if this is the problem or not, use the OBD2 scanner. (Check-Engine may have 3,000 reasons to ignite).
2. The car consumes more fuel
Due to incorrect fuel / air supply, the car engine will consume more fuel because it will no longer run at optimal parameters. Lack of air will be compensated with more fuel.
3. Stop the engine
If the engine stops at high speeds, then the EGR system certainly has problems, and for this reason, the life of the engine could be seriously affected.
4. Turbocharger malfunction
If the EGR & Cooler fan remains open and the exhaust does not cool, the result is as clear as possible, namely that the exhaust will not cool.
Once the engine overheats, the engine oil decomposes and starts the turbocharger, and for this reason the turbocharger suffers, no longer working.
Where is the EGR valve located?
If you intend to detect the EGR of your car, then you should definitely look around the car’s intake manifold, because you will most likely find it there. It is usually located on an intake pipe at the exhaust manifold.
Due to the heat, the screws will be removed with great difficulty, or they may be destroyed if you want to remove the EGR. For this reason, it is necessary to spray with a little WD-40 on the screws, before starting to loosen them.
Repairing or cleaning a bad EGR valve
There is a good chance that an EGR valve that has been broken and then repaired will work properly, but most of the time it is more cost effective to purchase a new valve than to repair the broken one.
Older EGR valves are simpler and easier to repair because they are vacuum controlled, and the repair procedure is as simple as possible. If your car has a vacuum controlled EGR valve, only the inside membrane can be replaced, and it can be cleaned so that it behaves like a new EGR valve.
When we discuss the EGR valves of newer generation cars, it should be noted that they have different electrical parts, so they are difficult to repair even by the best experts.
For this reason, and in this case, the most appropriate solution is to choose brand new EGR valves.
There are also newer generation cars, which have electric motors and have EGR, but spring valves. These can get stuck, and can result in cleaning and lubrication of the shaft, and thus destroy them.
If you like the idea of cleaning the EGR valve, in the first phase it is necessary to remove the curvature using a knife, after which you have to clean it several times using a special device built to clean the brakes.
After dealing with this stage, it will be necessary to lubricate the valve using WD-40, because in this way you will be able to make sure that the parts move properly.
If you find it much more convenient to change the EGR valve, keep in mind that if your car’s EGR valve is electronic, you must use the OBD2 scanner to remove the problem codes after the replacement.
Using this scanner is also necessary to make a basic setting for the new EGR valve. If you do not return the ideal parameters to the new EGR valve, you may later encounter the same error code, and thus you will most likely arrive with the car in service.
Once you have come to the conclusion that the EGR valve is faulty , you definitely need to repair it, so you can go with the car in service, so that the specialists can take care of this unpleasant situation.
If you do not like the idea of going with the car in service to replace this component, you must follow the steps below, to first clean the EGR valve, and then to remove the blockages and see if the mode valve operation is correct.
Therefore, first of all it is necessary to disconnect the car battery, after which you must disconnect the sensors and clamps, and then you must loosen the screws that hold the EGR valve.
Once you have completed all these steps, you will need to use a special device created for EGR cleaning, to clean hoses and valves.
After you have finished cleaning the hoses and valves, you will need to reconnect the car battery. It is extremely important not to allow the special cleaning substance to reach one of the car’s electrical components.
However, in order to clean certain electrical components, it would be advisable to use a special electrical device created for this purpose.
If you have not yet gone through such a process with your personal car, our recommendation is to take your car to the service so that the specialists can take care of this aspect.
Depending on the chosen car service, but also depending on the make and model of the car, and last but not least depending on its age, you will be able to pay more or less for this intervention.
How to detect a bad EGR valve?
The procedure required to detect a bad EGR valve depends very much on the EGR valve that the machine has. If you follow the steps below, you will personally fix the problem.
If you want to test an electronic EGR valve, for a vacuum controlled EGR, first of all it is necessary to perform a vacuum hose check between the inlet and the EGR.
You need to have a vacuum pump at hand that you can use with the soup to open the EGR valve, and to be able to see if the pressure is maintained.
If it is not under pressure, it is necessary to change the membrane if you have this possibility, or if not, to change the entire EGR unit.
It is also necessary to remove the EGR valve, and find out if it opens when you operate the vacuum pump. If the EGR valve behaves normally, it is necessary to check the solenoid, whose role is to control the EGR valve, and also here it is necessary to check the power
EGR controlled electronically
First of all you need to remove the EGR valve unit to see what the valve is opening and closing. Then, you need to connect a car battery charger when you are diagnosing to find out if the voltage in the car is good when the diagnosis is made.
The next step is to open and close the EGR valve using the OBD2 scanner. This procedure must be performed several times to check the function.
Then, it is necessary to perform a basic setting, and a reset of the saved parameter, with the scanner. It is also necessary to check all problems regarding the EGR wiring.
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Then you have to open the EGR valve and see if there is water inside the valve, or if there is corrosion infiltration, and it is necessary to use an electric cleaning device to clean the EGR valve if you find that there is corrosion.
Then reinstall the EGR valve and try again, this whole process, but if the EGR valve is faulty , then you need to replace it with a new one.
EGR valve on diesel engine
As for the EGR valves found on diesel engines, they are much dirtier, and need to be cleaned or replaced sooner. It should be noted that these valves are very likely to be destroyed due to carbon accumulation, so they need to be changed more often.
There are also drivers who have reprogrammed the EGR valve because if it no longer works, the amount of carbon that reaches the engine is lower. However, this is harmful for the environment, and those detected risk stinging fines.
Costs for EGR valve replacement
Depending on the make and model of the car, the costs for replacing an EGR valve can be between 49and 200 euros
Older cars are equipped with vacuum-controlled EGR valves, so drivers who own such cars may feel lucky, because they will spend less money if needed.
Newer cars, however, have an EGR cooler integrated with the EGR valve, so not only can the EGR valve be replaced, but the EGR cooler must also be replaced, and Volkswagen cars are an example in this case.
If, for example, an old car needs a new EGR valve, the price for this may be less than 100 euros For newer cars, however, the prices are higher.
Considering the fact that some prices can be quite high, it would be advisable that in case you need to replace the EGR valve, to take care of this car repair personally.
