What Is a Purge Valve?
Sometimes, it’s the little things that matter most.
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Seeing a check engine light can be frustrating. It’s even more frustrating when the problem causing that light is hard to diagnose and expensive to fix. If your blood pressure is rising, we apologize, but thankfully, though today’s topic can be frustrating and hard to diagnose, at least a purge valve is cheap and easy to fix!
You may have heard it referred to as the canister purge valve, but if you haven’t, it’s a small but important part of your vehicle’s emissions control system. Its failure won’t cause your vehicle to shake or smoke, but it can cause a real headache in a few other areas.
Identifying a failing purge valve will take a keen eye and a code scanner, but you won’t have to be a seasoned pro to replace one. The Drive’s editors can’t turn you into a master mechanic, but we can help you understand purge valves, what they do, and why they fail. Let’s dive in!
What Is The Purge Valve?
The purge valve, also known as the canister purge valve, is part of your vehicle’s evaporative emission control (EVAP) system. It traps the fuel vapors created in your fuel tank and prevents them from escaping into the air. The valve operates using a solenoid, which can sometimes malfunction and cause it to become stuck open or closed.
What Are The Symptoms Of a Failing Purge Valve?
When your purge valve fails or starts to malfunction, you’ll likely see a check engine light. If the vehicle’s computer senses an unusually high or low purge from the valve, it will kick an error code and illuminate the check engine light. Other common symptoms of a failing purge valve include:
Poor Fuel Economy
If the purge valve is malfunctioning, it can allow fuel vapors that your vehicle actually needs to burn to escape. The vehicle will have to use more fuel to produce the same level of power, causing a reduction in fuel economy.
Engine And Performance Issues
If the purge valve is stuck open, it can allow a vacuum leak to form. That means that air can flow into the combustion chamber at unexpected levels, which will mess with the engine’s air-fuel ratio and cause issues.
How Much Does It Cost To Fix?
The good news is that having your purge valve fixed won’t break the bank. All in, the cost to repair a broken purge valve will be somewhere between $100 and $200. Most of that cost is in parts, where the average price of a replacement valve can run up to $100.
Explanation of Purge Valve-Related Terms
In an internal combustion engine, the burning of fuel occurs in a combustion chamber. The expansion and pressure from the gases created pushes the engine’s components into action.
In order for combustion to occur, a specific ratio of air and fuel must be pulled into the combustion chamber. Each engine uses a slightly different ratio, which is controlled by the engine control unit (ECU). This ratio is referred to as the air-fuel mixture.
In vehicles, emissions refer to the gases that escape from the exhaust pipe during the process of burning gasoline.
Check Engine Light/Code
The vehicle’s computer constantly monitors the performance and working conditions of several components. If a part or system malfunctions, the computer will generate a code that can tell a technician where the problem is. In most cases, an error code will also lead to a check engine light, which is a visible indication of an issue inside the vehicle’s gauge cluster.
Sometimes You Need a Certified Mechanic
As much as The Drive loves to put the "you" in do-it-yourself, we know that not everyone has the proper tools, a safe workspace, the spare time, or the confidence to tackle major automotive repairs. Sometimes, you just need quality repair work performed by professionals you can trust like our partners, the certified mechanics at Goodyear Tire & Service.
FAQs About Purge Valve
You’ve got questions, The Drive has answers!
Q. Can I Ignore a Broken Purge Valve?
A. It’s certainly possible to drive with a broken purge valve, but we don’t recommend it. The longer you drive with a bad valve, the more risk you run of damaging the vehicle’s EVAP system and other parts. There’s also the possibility of wasting fuel and pumping out more emissions than is necessary. Think of the turtles here, man.
Q. How Hard Is It To Repair The Valve Myself?
A. The process of fixing or even cleaning a purge valve isn’t all that in-depth and shouldn’t take more than a couple of hours. That said, you’ll need to familiarize yourself with an OBD-II scanner and know your way around the various harnesses and wiring under your hood. Pick up a vehicle repair manual and you’ll be well on your way.
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You’ve got a world of choices when it comes to gear to help you with a failing purge valve. That’s why we’ve done the research to gather the best, most affordable, and most useful products that can have you identifying and fixing the problem at home in no time.
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