Is your EGR valve defective? Perhaps, you need to know the various signs showing that an EGR valve is damaged. Sometimes these signs show problems occurring in other parts of the system. So before diving headlong into repairs, you need to understand what it is, what these signs are and what to do to properly maintain an EGR valve.
What is an EGR valve?
Exhaust gas redirection sounds like a self-explanatory term, but its application is both complicated and sophisticated. The EGR system redirects the exhaust gases into the intake manifold and uses them for combustion.
This process not only reduces harmful emissions of nitrogen oxides (Nox), but also helps the car stay within legal pollution limits. When the exhaust gases are recycled, the combustion temperature decreases, thus preventing the production of NOx. There are also some drawbacks to reducing fuel emissions, such as loss of fuel economy, poor performance, and in cars with diesel engines, soot production increases.
However, modern engines use smart technologies for an efficient process. For example, newer diesel engines now use the EGR cooler which cools the exhaust gases by passing the coolant through.
Cost of repairing an EGR valve
Repairing an EGR valve can sometimes work, but in most cases it will cost less to buy a new one. Older vacuum-controlled EGR valves are easier to repair because their function is much simpler. If you have a vacuum controlled EGR valve, you can often replace the diaphragm inside of it and clean it to work as a new EGR valve.
New EGR valves contain many electrical parts and can be very difficult to repair if you are not an expert. It may also be impossible to find replacement parts for the interior of the EGR. Most likely you will need to buy a new one.
The average cost of replacing an EGR valve is between $ 250 and $ 600, depending on your car model. The labor costs are most often between 50 and 150 € and the cost of the part between 50 and 400 €.
To have the best possible estimate, it is better to directly quote to change the EGR valve. Going through this step will allow you to realize the amount of the invoice and you will be able to prepare for it.
The various signs showing a faulty EGR valve
Since EGR deals with exhaust gases such as carbon dioxide and NOx, it may become damaged or clogged over the years. This, in turn, reduces the performance of the car and also increases pollution.
The EGR valve remains open
If the valve is left open, a continuous flow of exhaust gas enters the cylinders, disrupting the combustion process. The engine idles erratically, experiences power surges and even jams when it heats up or when driving at low speed, in a parking lot for example.
If the valve becomes blocked or the passages become blocked
The temperature of the cylinders will rise, causing a shock (fuel ignites before combustion), you will notice a tapping sound from the engine. In severe cases, this will cause loud bangs that will seriously damage your engine.
If the Check Engine Light comes on
On newer car models with electronic valves, the vehicle’s computer will trigger the Check Engine Light or Malfunction Indicator Light (MIL) if there are problems with the EGR system.
This happens when the engine is running at low revs and the EGR valve remains open, allowing additional throttle to result in a drop in engine performance.
Black smoke from exhaust gases
If the EGR valve is left open at all times and the exhaust gases are continuously feeding the engine, the engine is starved of oxygen. With too much fuel and less oxygen, black smoke arises and comes out of the tailpipe, especially when the car is idling.
Cleaning the EGR valve is simple maintenance that will extend the life of your engine. It is also necessary to do your annual check of the vehicle, to keep it in good condition. Just make sure to clean it properly to avoid unintentional damage if you don’t replace it directly.