The exhaust gas recirculation system (EGR) is one of those humble car systems that simply does its job in the background.
But this system makes a really important job. Longer mileage, less pollutant emission, and a more efficient engine. You owe all of these things to your EGR system.
However, just like any device, the EGR system can fail or malfunction. This is the reason why you should be vigilant in case the symptoms of a bad EGR valve may manifest.
On this page, we will tackle lots of information about your car’s EGR system, from the basics to its symptoms.
Getting To Know Your EGR Valve
Diesel Engines have this so-called exhaust gas recirculation reduction system. It is a nitrogen oxide emissions system that functions by recirculating some volume of the exhaust gas back to the cylinders inside the engine.
The purpose of an EGR valve is to meet the standards of your existing government and at the same time, reduce the amount of emission your car releases to the environment.
The EGR valve is responsible for recirculating a portion of the exhaust gases back to the engine. Though these gases contain very little oxygen, they are really hot and still contain unburned fuel.
These elements contribute to the combustion process. Since the engine recycles some exhaust gas as catalysts for combustion, it will now consume less fuel to burn.
The problem with an EGR valve is they can clog or leak over time. This possible phenomenon imposes additional problems – your vehicle performance may run poor and more, uncontrolled emission goes out to take part in the rising pollution.
Good news is you can diagnose the problem by yourself and you can actually make actual repairs to end the problem.
Symptoms Of A Bad EGR Valve
There are several tell-tale signs indicating a bad or failing EGR valve. The symptoms don’t necessarily appear together but you can surely observe one or two while driving.
There are also cases where the signs won’t occur until the valve already has serious issues. If you are driving a car with an EGR system, here are some of the signs you should look out for.
1. Experiencing Rough Idle
One of the first symptoms that will manifest with a failing EGR valve is a rough idle. It is not surprising for EGR valves to become stuck in the open position and malfunction after periods of driving operations.
When conditions are not in your favour, a faulty EGR valve promotes excessive recirculation of exhaust gas which will further cause rough idle.
2. Issues in Engine Performance
Another symptom that can happen in the earliest stages of an EGR valve malfunction is a series of engine performance issues.
You can observe less fuel efficiency, difficulty in acceleration, or a loss of power. A malfunctioning EGR, or a clogged one, can disturb your car’s air-fuel ratio.
When the engine experiences imbalance in the air-fuel ratio, there wouldn’t be enough catalysts in the combustion process. The loss of this process will cause the overall functionality of your car to cripple.
3. Check Engine Light Activates
Now here comes this annoying little yellowish light. When the check engine light turns on, it means your car’s computer system detects a problem(s) within your vehicle, hence check engine. One example is an out of order EGR valve.
The check engine light will notify you if there’s an issue with your EGR position or valve circuit. However, the check engine light could also mean other possible car problems and not just an EGR malfunction.
For confirmation, it is best to have a computer scan for the codes in trouble. You can also read this article entitled, how to reset check engine light to have your light and codes reset.
If your vehicle has an EGR system, you can track the problem through the PCM memory that stores diagnostic codes.
The computer will display these codes in your check engine light. The light will turn on, alerting you with specific issues in your engine. Thanks to this light, diagnosing the problem becomes quite easy.
Here are the problem areas with their corresponding codes:
EGR valve is stuck open
EGR valve in pintle position
EGR system flow is inefficient
EGR solenoid circuit problem
EGR system performance
EGR pintle position circuit low voltage
4. Can’t Accelerate Enough
Did you ever experience a bad acceleration? If you really know your car, you can easily tell that it can’t speed up the way it does before. This condition could indicate a bad EGR.
If the exhaust gas recirculation valve is clogged, there wouldn’t be enough exhaust gas to enter the intake valve. Atmospheric air wouldn’t be enough in the combustion process.
As a result, less power is produced. This problem will spiral down to the last part of the cycle which is exhaust, which will then repeat the problem again and again.
You can expect an obvious drop in your horsepower, particularly when your EGR valve is stuck open. Under hard acceleration, you can observe a “ping” or “knock” detonation while the cylinder misfires.
5. Hard Starting
Another symptom is having difficulties in starting the engine. This is quite a common problem still when the EGR valve is stuck open. You can consider an open EGR as a massive vacuum leak so you can anticipate a very rough idle (explained above) and a very unfortunate hard starting.
- Hot catalytic converter
- Exhaust pipe giving off fuel smell
- A very obvious less fuel economy
These symptoms are common when the EGR valve is clogged with carbon, or when it is simply stuck closed. A closed EGR valve won’t produce lots of symptoms but it is still an issue that needs attention.
A noticeable drop in fuel economy is imminent with a clogged EGR. Since there’s not enough exhaust gas to recirculate, your engine will consume more fuel to compensate for what is lacking in a normal operation.
You may like this: Why Your Car Smells Like Gas
A Stuck Closed EGR Valve
A spark knock happens when the air-fuel mixture already ignites without reaching the cylinder explosion first.
Your vehicle also begins to “knock” when the EGR valve is stuck close. When this happens, large quantities of emission will come out from your car.
Knowing and Fixing a Clogged EGR Valve
Take a look at your check engine light display. If the error code says P1406, it means there are carbons blocking your EGR valve. You can also utilize a multi-meter. It saves you time and helps in diagnosing other valve issues.
Now remove the valve. Grab a valve cleaning kit and start removing all types of debris choking your valve.
When the exhaust gas does not recirculate back to the engine at idle, lots of carbon will gather in the valve, eventually blocking it. This usually happens at 30 mph and above. Having chunks of carbon blocking your EGR can cause frequent stalling and rough idles.
Knowing and Fixing a Closed EGR Valve
Now diagnosing this one is a two-man job. Take a look at your check engine light display. If the error code says P0401 or P1406, it means the EGR valve is stuck closed. You can also do a physical inspection to confirm. Have someone observe if the EGR valve moves while you rev up your car in park position.
Just like a clogged condition, remove the EGR valve and then utilize a cleaning kit to get rid of all debris stuck in there.
A Stuck Open EGR Valve
Now this one’s a little more serious problem. Rough idling due to inefficient combustion is the most common tell-tale. You can blame the vacuum leak created when the EGR valve is stuck in the open position.
In more extreme cases, you can even experience stalling. Normally, your engine needs atmospheric oxygen in the combustion process added with some recycled exhaust gas (with little oxygen) to be more efficient. However, a stuck open EGR valve can overwhelm the combustion chamber with exhaust.
Knowing and Fixing a Stuck Open EGR Valve
Take a look at your check engine light. If the display says P1406 or P1404, it means the EGR valve is stuck open. You can also physically check the plunger shaft while your vehicle is idling and parked.
Another way of diagnosing a stuck open EGR valve is to remove the valve itself. Get a carbon cleaner and fill the valve with it. You can know the valve is open when the fluid leaks out when you turn it upside down.
Now get a valve cleaning kit then utilize tools to pull a vacuum on the valve.
A lot of car function suffers when you have a failing EGR valve. Knowing the symptoms of a bad EGR valve is the first step in properly diagnosing this common car issue.
If you start noticing these signs in your EGR-system-equipped vehicle, it is best to aid the problem immediately.
Pay attention to the issues right away to avoid further damage. Remember, repair costs are generally less expensive than replacement parts.