Driving With Bad Purge Valve | 100% Fixed

Photo of author

rebbeca jones

This article examines an important component of a car’s engine, the purge valve, and delves into its potential issues and solutions. It explores bad purge valve symptoms and provides DIY tests to answer the questions: what is a purge valve, what happens when you drive with a faulty one, and how can you address such issues with ease?

Driving With Bad Purge Valve

It is essential to understand the vehicle one is driving to ensure that one can tackle a failing engine in case of emergencies. Not everyone wants or can make sense of the mechanics of an engine, which is not for everyone. Still, a basic knowledge of the car components is necessary for all drivers to ensure a safe driving experience. ‘Driving with bad purge valves’ is a common overlook made by drivers. We will break down this component, starting with the basics: What is a purge valve?

Defining a Purge Valve

Before we get into faulty purge valve symptoms and possible solutions, let us first answer the question: What is a purge valve?

A purge valve, also called the canister purge valve, is part of a car’s EVAP system. EVAP stands for Evaporative Emission Control System. As the name suggests, this system entrapped the fuel vapors created in the vehicle’s tank. This is done to ensure that these fuel vapors escape freely through the engine so the car can burn them quickly. Are they moving on to the following question: How does a purge valve work?

Now that we know the answer to ‘what is a purge valve,’ let us go forward to the ‘how does it work’ part to understand better the bad purge valve symptoms described in the latter sections.

The fundamental function of a purge valve involves a solenoid mechanism that captures fuel vapors and stores them temporarily in a charcoal canister to prevent them from escaping and being wasted.

It’s worth noting that these solenoids may malfunction and become stuck in either the open or closed position, resulting in adverse symptoms associated with a faulty purge valve. Furthermore, such malfunctions may have severe long-term consequences on the vehicle.

Driving with Bad Purge Valve: Analyzing The Purge Valve 

Your purge valve can be solenoid or computer operated; it should be noted that most modern vehicles use the latter, which works on the electrical operation commanded by the engine’s computer.

When the engine is not running, the computer closes the valve and gradually opens it when turned on. Through this gradual process, fuel vapor quickly moves and burns to ensure proper movement of the vapors.

It is challenging to navigate a car engine if you are not into cars, but the purge valve is pretty easy to locate, even though it may seem hidden amidst the similar-looking parts of the engine. In the case of most cars, the purge valve is placed atop the engine. It is connected to a circuit and is mounted between the engine and the radiator. 

Now, we have discussed sufficient information about the purge valve to understand it enough to move on to the main problem and its repercussions which cannot be understood without answering ‘What is a purge valve,’ which we have discussed in depth here.

Engaging Read –  Car Turns Off While Driving But Turns Back On; Steps to Fix

Driving With Bad Purge Valve: Repercussions 

If your purge valve is damaged, it will not harm your vehicle, and you may not be able to notice noticeable changes like you do in the case of a flat tire or dying battery, etc. If you see a faulty purge valve while driving, you do not have to fix it urgently. This does not mean that you do not need to get it checked at all.

If a car with a faulty purge valve is continuously driven over time without getting fixed, the problems caused will evidently increase and will be reflected in unavoidable and troublesome symptoms.

The repercussions can even turn fatal, as one of the possibilities is carbon buildup near the valve, which can lead to the emission of toxic and poisonous gasses. 

Driving with Bad Purge Valve: Bad Purge Valve Symptoms 

If your car exhibits any of the following symptoms, it is essential to have a mechanic examine it promptly. Delaying necessary mechanical repairs and check-ups is never advisable.

Moreover, while some of these symptoms may be indicative of other mechanical problems, it is still advisable to have your purge valve inspected in case of any issues.

Here are some bad purge valve symptoms to watch out for:

Check Engine Light

The check engine light blinks for various reasons, all of which cause concern for your car. One of them is a faulty bad purge valve as well. If the car’s vehicle’s computers detect an abnormally high or low purge from the valve, it causes the check engine light to blink, which should be your cue to get your car to the mechanic as soon as possible.

Bad Fuel Economy

A faulty purge valve is directly connected to fuel consumption, making bad fuel economy one of the most common symptoms that one should keep an eye out for.

As mentioned above, the purge valve ensures that fuel vapors escape properly to be burned to create power. If something is wrong with the purge valve, i.e., if it is obstructed or clogged, more fuel vapors will be required to burn to obtain the same amount of power, resulting in poor fuel economy.

Engine and Performance Issues

This is another common bad purge valve symptom, closely connected to the one discussed above. We discussed symptoms caused if the valve is clogged; what happens when it is stuck open?

If so, there is a huge possibility of a vacuum leak forming, meaning that air can flow right into the combustion chamber, which messes up the engine’s air-to-fuel ratio causing its performance to decline.

The creation of said vacuum leak is one of the most common bad purge valve symptoms, but what can be done if our engine also falls prey to it? How can one identify that one has a vacuum leak?

When experiencing faulty purge valve symptoms, one common issue is a vacuum leak that can be identified by a distinct hissing sound when the car is idling. This can lead to worsened emissions, as faulty purge valves allow unwanted gases to enter the combustion chamber, resulting in the release of more pollutants during the burning process.

Rough Running After Filling It Up With Gas

Driving with bad purge valves makes the car rough, unstable, and idle. This is most noticeable when the car’s tank is freshly filled with gas. This is due to the high density of fumes in the engine at the moment. 

Failure in Emission Inspection

In order to register a vehicle in the state, it must undergo emission inspection tests and pass. Purge valve related issue should be resolved before the test as there is a high chance that it will prevent the vehicle from passing the test.

As mentioned before, the purge valve plays an essential role in the emission of gasses after combustion and thus needs to be fully functional to ensure that the emissions do not go out of hand.  

Driving With Bad Purge Valve: Testing a Bad Purge Valve Symptoms Showing The Solenoid

If you feel that your engine is showing one or more purge valve failure symptoms, the best course of action is to check it yourself or get it checked to ensure that everything is alright. As mentioned before, purge valves work using a solenoid.

It can be checked in two ways, requiring a vacuum test. If you are not handy with engines, getting it checked with a mechanic is advisable.

The Simple Method

Open the hood of your engine and locate your purge valve. If you feel your solenoid is stuck open, all you need to do is remove and blow it into it. If the air successfully passes through, the solenoid is open; otherwise, you could have a vacuum issue.

The Vacuum Test 

A more particular and dependable way of identifying potential issues with a faulty purge valve involves creating a vacuum on one side of the valve. However, it is advisable to seek assistance from a qualified mechanic instead of attempting this alone, especially if you are unfamiliar with the engine’s structure.

To perform the test, you will need a vacuum tester to generate the pressure to trigger the purge valve to open. Additionally, 12V power is required to connect to the valve for it to operate.

Driving With Bad Purge Valve: Locating a Bad Purge Valve

If you have essential tools and are handy with machinery, you can do most of these listed remedies yourself. Follow the given steps:

  • If you are facing purge valve malfunction symptoms, the first step you want to do is to test the valve. You can use the above-described methods or more.
  • Ensure that your engine is turned off before you work on it. This should be done to cool down the engine. One should wait up to thirty minutes before beginning any work on the engine after shutting it down.
  • Locate the purge valve and perform a continuity test which can be done quickly. Disconnect the valve, use a multimeter, choose a continuity mode, and listen to the produced sound. Hearing a sound indicates the valve is working; if not, it reflects some damage.
  • You can also take an ohm-meter reading of the purge valve by putting the two probes of the multimeter on the power terminals of the valve. Your typical reading should range from fourteen to thirty ohms; any number higher or lower indicates damage.
  • You can also do the mechanical click test by connecting the probes to a twelve-volt battery terminal and the other to the valve. If it clicks, the purge valve is working fine; if not, you need to get it looked at as soon as possible, as driving with bad purge valves, like before, can negatively affect the vehicle.

Interesting Read – How To Reset Service Stabilitrak Light? | Easy Steps 

Driving with Bad Purge Valve: Cleaning a Bad Purge Valve

Here are a few steps for cleaning your car’s purge valve, which can be a wise decision if you are experiencing symptoms associated with a faulty purge valve:

  • One way to clean a dirty purge valve is to use a Carb cleaner or sprayer. This powerful liquid cleaner comes in a tin can and uses high pressure to remove dirt from the valve.
  • Another method involves manually cleaning the valve by pulling it out and holding it with your fingers. Vigorously shaking the component can help remove clogged dirt or debris without causing any damage.
  • If the vapors inside the engine turn into liquid, they may block the valve, leading to low engine performance and other technical issues. To prevent this, it is possible to release these vapors by opening the end of the valve.
  • Alternatively, you can use contact cleaner to clean the valve, but it is important to ensure that it is completely dry before using it.

If you are uncertain about the symptoms associated with a faulty purge valve or unable to fix the problem on your own, seek the assistance of a professional.

Driving With Bad Purge Valve: Replacing The Bad Purge Valve

As mentioned various times before, driving with a bad purge valve is not a good idea. You can clean it using the methods described above, but sometimes a valve gets too damaged, and cleaning is not enough and needs replacing. Getting this done by yourself can be tricky, so it is advisable to hire a mechanic or handyman to get it done. Ensure to look up prices of the new purge valve before you go to get the work done.


Some frequently asked questions about Driving with bad purge valve have been answered below:

How long can you drive with a bad purge valve?

Even though driving with bad purge valves is not recommended, it is not an urgent concern. It would help if you did not let your car go forward more than thirty to fifty miles before getting the problem fixed.

Can a bad purge valve damage the engine?

Yes, a bad purge valve can most definitely damage the engine it is a part of, but this is gradual damage.

Is getting a bad purge valve replaced expensively?

The cost of getting a purge valve replaced depends on the place you are getting the work done, as labor costs are a big part of it. The new purge valve will cost from about thirty to a hundred dollars.

Can bad purge valve cause loss of power?

Loss of power is one of the five symptoms of a defective, bad purge valve. Other symptoms are difficulty starting the engine, the car not accelerating smoothly, the engine running rough, and the check engine light is turned on.

What happens when a purge valve is stuck closed?

If the vapor valve is stuck closed instead of being open, the valve won’t send any fuel vapors back to the engine. Instead it will extract out of the exhaust, which will cause higher emissions.


It is crucial to keep in mind that prevention is always better than cure. If you notice bad purge valve symptoms, do not ignore it or rule it out as a repercussion of prolonged use and get it checked at once! Your safety lies in your own hands.

Thanks for reading. Have a lovely day.

About the author
rebbeca jones

Leave a Comment