Bad EGR Valve

The Exhaust Gas Recirculation or EGR valve functions to help reduce emission. This is an important component of vehicles, especially trucks. However, it can also be damaged causing automotives to malfunction.

Here are five symptoms of a bad egr valve. [] Knowing these symptoms will help you care for your vehicle and maximize its usage.

Rough idle when starting the engine

Egr valve has one main function. It either opens and directs exhaust gases into the combustion chamber, or closes and keeps them from entering. When there is a rough idle when you start the engine, especially when the engine is cold or when you are at a stop light, the egr valve could be in bad shape.

Increased in fuel consumption

Fuel gases get in and out of the egr valve in controlled amount. As your engine starts to work up, gas flow through the valve and keeps your engine running smoothly.

If you notice that your fuel gauge register a dramatic decrease in your usual consumption, it’s time to check the egr valve for leaks. Do not take it for granted. If you own trucks, gas consumption due to problematic egr valve can eat up your overhead cost.

Failed emission test

Because the egr valve’s main role is to reduce emission, a failed emission test is one of the most telling symptoms of a bad egr valve. [] No doubt about it.
The egr valve keeps outside air, exhausted gas and fuel from constantly entering the vehicles intake manifold. According to mechanical experts, when outside air combines with the fuel and ignites in the combustion chamber, temperatures can reach above 2500 degrees Fahrenheit (or 1370 degrees Celcius). At this temperature, nitrogen gas burns creating the toxic element oxides of nitrogen or NOx gases. This is harmful to the environment and human health.

Furthermore, hydrocarbons are not efficiently burned. As a result, it leaves blackened tailpipes.

Loud detonations

The egr valve encounters problem either from prolonged opening or failure to close. If the egr valve failed to close, a common symptom is a constant pinging or rapping noise at low engine RPM leading to a loud detonation after second ignition.
As the engine revs up, the temperature in the combustion chamber increases. The fuel should not enter the egr valve at this point. When you go for a second ignition, fuel enters the egr valve again and combines with the first fuel, causing a loud noise. This can damage your car’s engine.

Check Engine light, or Malfunction Indicator Light (MIL)

If the egr valve is in trouble, the Check Engine light, or Malfunction Indicator Light (MIL) on the dashboard will light up. Depending on your vehicle’s model, the computer circuit system will detect a problem in the engine and alert the driver.
A malfunctioned egr valve is just one of the many problems that can be detected by the indicator. If it lights up and you notice any of the other four signs of a bad egr valve, [], you need to have it checked as soon as possible.

While you can replace the egr valve if you have the skills, it will be better to go to a reliable garage and have a technician check the engine.