Is your BMW equipped with an engine gas recirculation (EGR) valve? These valves are useful additions to vehicles to help reduce our greenhouse gas emissions, specifically nitrogen emissions. They also help to cool part of the engine. However, many BMW owners find that they have a bad EGR valve. BMW has issued at least one recall over EGR valves and valves in other models have been known to act up too. If you own a BMW you may want to familiarize yourself with the signs of a bad EGR valve so that you will know if your valve needs replacement.
Signs of a Bad EGR Valve
While there are many different kinds of EGR valves, the basic concept is the same. The EGR reduces the temperature in the combustion chamber, using the vehicle’s own exhaust. This drop in temperature helps reduce the number of nitrates that the combustion chamber makes. That’s because nitrates are only made at very high temperatures. The valve is designed to open and close as needed in order to modulate the When there are EGR problems, your vehicle will have emission and performance problems.
Here are the signs of a bad EGR valve:
- Lowered engine power: Is your BMW as responsive at green lights as it has always been? If your vehicle no longer seems as powerful as it once was, then the problem could be a bad ERG valve. The valve can ruin the air to fuel ratio in your combustion chamber, undermining its power. This is especially true during acceleration.
- Lowered fuel economy: When your vehicle has to work harder to respond to the gas pedal, it will use significantly more fuel and reduce your overall fuel economy. Allowing a bad EGR valve to undermine your vehicle’s performance for a long time can result in much more costly gas and a big impact on the environment.
- Odor from the exhaust: The fuel odor won’t change, but it will be more intense when you have an EGR problem. The exhaust will create more hydrocarbons which is what causes the smell. You may even smell the exhaust when you’re inside of your BMW, and that’s a sure sign you need to take it into the shop.
- Emission test failure: Of course, an emissions test failure could be a problem with the EGR valve, in fact, that is very often the case. If you suspect you have an ERG problem and you have an emission test coming up, it is best to get the valve looked at first. Failing the test is a hassle and you’ll have to get the valve problem fixed anyway.
- Misfire: Misfiring is a rare symptom of a bad EGR valve, but it can still happen. Very poor EGR valve problems can change the fuel-to-air ratio in the engine so much that it misfires.
- Rough idling: While a rough idle can be the sign of many problems, an EGR valve is a potential cause.
- Check engine light: As with the idling, the check engine light is a symptom of many potential problems with your BMW. The EGR valve is just one possibility. However, combining the check engine light with another issue on this list would make the valve a more likely possibility.
If your BMW is experiencing any of these problems, then it is wise to get it checked out by a professional.
Potential EGR Problems
So, your BMW has the symptoms of an EGR valve problem. What could be going on? The two main possibilities are that the valve is stuck open, or that it is stuck shut. Both have different symptoms.
- Stuck open: If the valve is stuck open, you’ll notice that the check engine light comes on, the BMW uses more fuel, has lost power, and may stall when the engine is idling. The vehicle will also have increase exhaust small and will particularly struggle at low speeds.
- Stuck shut: If the valve is stuck shut, you’ll notice fewer issues. The check engine light will come on. There may be a tapping noise when you’re at low speeds. You may notice a second ignition or a loud bang. But the biggest sign is often failing an emissions test.
There are five main types of EGR valves, so there are many other possible problems with the valve. It’s best to reach out to the professionals to have them diagnose your BMW’s ERG valve issues.