5 Symptoms of a Bad Vapor Canister Purge Valve (and Replacement Cost)

5 Symptoms of a Bad Vapor Canister Purge Valve (and Replacement Cost)

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 Is Done during Canister Purge Valve Replacement?

The procedure isn’t the same for every canister purge valve. Some of them are placed near the fuel tank, while others are near the engine, and the technician will need to locate the valve and diagnose its condition before taking it apart or replacing it.

Once the technician finds the valve, he will need to remove any parts that are in the way. This could be any number of items, and they will vary based where the valve is located. The valve will be disconnected from any hoses, and a new valve will be put in its place. Then the hoses will be reconnected, the parts will be put back in place, and the technician will test the new valve.

How to test the canister purge valve

If you are trying to determine if you need to repair the valve or if you need to figure out the total canister purge valve replacement cost, then you will have to test the canister purge valve. You can find the right procedure to test the purge valve in the service manual for your specific car. The procedure is different depending on the car’s make and model, while the purge valve is usually closed during use.

If the vehicle service manual recommends that you apply battery voltage to the purge valve terminals, this can help you determine which end provides an audible click. The next step is to test if the purge valve closes properly and does not show any leaks during use. If the canister purge valve is leaking, then you will need to look up the canister purge valve replacement cost.

To find the leak, you need to connect a handheld vacuum pump and apply the vacuum to the canister purge valve. When this happens, the vacuum should not drop almost right away. If the vacuum pressure drops this means that the canister purge valve is not sealing properly and must be replaced. The car might also have the check engine light turned on the dashboard and you should use a diagnostic tool to check for any trouble codes. 

The trouble code can alert you to whether the evaporative emission control system vent control circuit is malfunctioning and can determine the source of the leak in the bad canister purge valve and help you get closer to the total canister purge valve replacement cost.

To find the difference, you might need to test the canister purge valve from a different car. If the canister purge valve holds the vacuum well, then this means there is an issue with your own car. After this step is complete, you need to connect the battery voltage. The purge valve will click and the vacuum drops, showing the purge valve is working correctly and you do not need to look at the canister purge valve replacement cost.

Bad Vapor Canister Purge Valve Symptoms

If you have a bad vapor canister purge valve, the symptoms that you experience will potentially be worse than the symptoms of a bad charcoal canister. You need to understand what these symptoms are if you are going to tell the difference between the two possible problems.

Here are five things to look out for:

1) Check Engine Light

There are dozens of reasons for the Check Engine L

There are dozens of reasons for the Check Engine Light to illuminate on your dashboard. If you have a damaged or worn out purge valve, this could possibly cause the Check Engine light to come on.

There are sensors which detect when the purge valve is working. But if there are no signals coming from the purge valve anymore, this will indicate to the sensors that the valve must be damaged.

The sensors will then relay this information back to the engine control unit, which will result in the Check Engine warning being given to you.

2) Rough Idle

If your car engine has a rough idle, then it is no

If your car engine has a rough idle, then it is no longer running smoothly. It will run at an inconsistent rate as you’re driving, especially when stopped at a stop sign or red light.

The longer you continue to let this problem persist, the more consistently your engine will run. The worst point will be when your engine stalls altogether.

Try not to let it get this out of hand. Usually, when the purge valve is to blame for the rough idle, it will cause a vacuum leak which will impact the idle speed.

3) Trouble Starting Car

If you have a vacuum leak that was brought on by a

If you have a vacuum leak that was brought on by a bad vapor canister purge valve, then you will probably have difficulties starting your vehicle. This will cause outside air to uncontrollable enter your engine and interfere with the overall internal combustion process.

If you have unmetered air mixing with fuel in the cylinder chamber, then it will cause engine problems for sure. The most obvious problem will be an engine that does not start.

4) Poor Engine Performance

If you are able to start your vehicle with a bad v

If you are able to start your vehicle with a bad vapor canister purge valve, don’t expect it to be a smooth ride. You will almost certainly experience weaker performance from your engine.

In other words, your engine won’t be able to generate as much power to provide the acceleration that you are demanding as you press down on the gas pedal. This will be most obvious when going uphill or attempting to pass another vehicle.

5) Emissions Test Failure

As you know by now, the vapor canister purge valve

As you know by now, the vapor canister purge valve is responsible for redirecting fuel vapors back into the engine. This is preventing toxic hydrocarbons from being emitted from your tailpipe.

So, if you were to have a failing purge valve, then it wouldn’t be able to redirect those fuel vapors and prevent them from escaping your vehicle. You will find this out the hard way when you go for your emissions test and end up failing.

If this happens, have the mechanic check your purge valve to see if it’s the part responsible for the failed emissions test. If it is worn or damaged, then you will need to replace it promptly. Then you should be able to pass the emissions test.

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.

Canister Purge Valve Replacement: Can I Do It By Myself?

You can replace the canister purge valve yourself, but only if you have mechanic expertise and a bit of experience replacing one or two before.

If you are completely new to scrutinizing and fixing an engine part, it could be a difficult task for you. This video could help you understand the purge valve system a little better.

If you are willing to replace the purge yourself, you should be able to find the valve, to begin with.

The location of the purge valve can be a little tricky to identify if you don’t have some prior knowledge about the possible locations of the valve. The spot could slightly vary depending on the engine and primarily on the model of the car in question.

If you are looking at the engine of the car from the front side of the engine, you can inspect the left area of the throttle body, also referred to as the butterfly valve. There, you would be able to find a purge valve on the engine intake. While this is fairly easy to find, another possible spot that might require you to look into is at the back of the fuel tank.

Depending on what type of car you use, if your purge valve is located on the engine, it would not require much time for the complete canister purge valve to be replaced. Yet, if the canister valve is with the fuel tank, it could take a mechanic up to 2 hours to replace the valve.

A purge valve is an integral part of your EVAP system, faults in the replacement could leave to complete engine stalling as well. Hence, all being said, it is always the best practice to trust the hands of a professional mechanic.

Next Step

Schedule Canister Purge Solenoid Replacement

The most popular service booked by readers of this article is Canister Purge Solenoid Replacement. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews… LEARN MORESEE PRICING & SCHEDULING

Vapor Canister Purge Valve Replacement Cost

Best places to order parts?  See: 19 Best Online Auto Parts Stores

Replacing a canister purge solenoid is a pretty st

Replacing a canister purge solenoid is a pretty straightforward type of job that doesn’t cost too much. Expect to pay anywhere from $80 to $200 in total.

The part will typically cost anywhere from $30 to $120, while the labor costs will be right around $50 to $80. Then, of course, there are fees and taxes added on to this price too.

Replacing the purge valve yourself is very doable so you can save a few dollars on labor.

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Vapor Canister Purge Valve Location

Depending on what you drive, there are two typical

Depending on what you drive, there are two typical locations for the vapor canister purge valve.

The Canister purge control valve is most often located in the engine bay on a hose going from the intake to the canister. It can also be located near the fuel tank.

The component won’t look like much. Typically, it’s nothing more than a little black plastic component with an electrical connector and a vacuum line on each end. While it can be hard to identify, it’s usually pretty easy to access once you’ve found it.

How to Save Money on Canister Purge Valve Replacement

If you want to save some money on this procedure, then you can check around for the best rate. The price of labor and parts may differ from one mechanic to another, but you aren’t likely to see a huge difference by choosing one mechanic over the competition.

You can do the job yourself as well, as it won’t take very long and it is not terribly complicated, but you ought to know what you are doing. You can end up damaging the vehicle or not installing the parts properly if you are inexperienced.

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