Bad Charcoal Canister Symptoms To be Aware Of

When the fuel burns, it emits some vapors, which are responsible for a kind of evaporative emission pollution. These vapors are toxic and detrimental to the environment, given they get released. But automobiles are equipped with a charcoal canister that keeps these pollutants deposited. You must be aware of bad charcoal canister symptoms to avoid an emission test failure and fueling up air pollution.

Basic Functions of a Charcoal Canister

A charcoal canister is a component of the evaporative emission control  (EVAP) system. Its main function is to catch the fuel vapors before they get released to the outside environment.

The charcoal in the canister keeps the vapors trapped for some moments before recycling them back to the engine. There is a purge valve that enables this fuel flow. The Engine Control Unit (ECU) signals the EVAP system about the right timing of activating the purge valve.

bad charcoal canister
The charcoal canister keeps toxic emission in check. (Photo Source: wallsheaven)

A charcoal canister reduces automobile air pollution by trapping the toxic vapors inside. A petrol engine must have this component because it produces vapors at a rate quicker than diesel engines. Warm weather also quickens the evaporation rate.

Top Bad Charcoal Canister Symptoms

A malfunctioning charcoal canister will create so many problems from a vehicle. It affects the engine performance, fuel economy, and so many other things. You need to pick up the warnings at an early stage before they transform into something worse.

Here are a few most common bad charcoal canister symptoms to keep an eye out for.

High Rate of Emissions

This is obvious since the charcoal canister’s job is to trap toxic vapors. When the canister cannot do that, a high amount of harmful gases will be released to the environment. As a result, the exhaust system will release a higher rate of carbon emission.

Unfortunately, a surge in the exhaust discharge is hard to detect without an emission test. In the USA, every automobile has to undergo this testing every one or two years, depending on the state laws. If the car fails the test, the first component to look into is the charcoal canister.


Fuel Odor in the Cabin

As a defective charcoal canister lets out burnt fuel vapors, there will be a strong fuel odor inside the cabin or rear side of the car. Inhaling these noxious smokes are not good for health. Take the vehicle immediately to a repair shop to find out the source of this problem.

Weak Engine Performance

Poor engine performance is a major red flag. The fuel vapors not getting back to the combustion chamber will create a problem with the air/fuel ratio, affecting the engine’s power. It cannot harness adequate power due to an incorrect ratio or burning of the air/fuel mixture. Due to weak engine power, the acceleration becomes slower. It does not respond as quickly as it should be whenever you step on the gas pedal.

Bad Fuel Economy

Any trouble with the engine is likely to be followed by a bad fuel economy. When the fuel vapors don’t make their way back to the combustion chamber, the engine will draw more fuel from the fuel tank than it’s supposed to. So, you will need to spend more on the fuel than you are supposed to.

Pinging Sounds from the Engine

Pinging sounds from the engine result from improper air/fuel mixture in the combustion chamber. It could happen when the charcoal canister does not trap and recycle carbon emissions.

Of course, the source of trouble could be some other components. However, if the sounds come with a few other bad charcoal canister symptoms from this list, you should definitely diagnose the EVAP system.

bad charcoal canister symptoms
Pinging sounds indicate a bad charcoal canister. (Photo Source: cars)

Trouble Starting Engine

A bad charcoal canister can lead to a vacuum leak, which makes starting the engine a strenuous job. This leak lets in plenty of outside air, disrupting the ideal ratio of the air/fuel mixture. So, the combustion in the chamber may not be sufficient for the engine to start.

The vacuum leak also causes a rough idling problem, and you will notice this after the Check Engine Light comes on (which can be triggered by literally hundreds of things). This problem messes up with the idling speed of the engine and leads to rough idling.

Charcoal Canister Replacement Cost

Upon detecting one or multiple bad charcoal canister symptoms, your first job should be to take the car to a mechanic. How much does replacing a charcoal canister cost?

The price range varies depending on the make and model of your vehicle. The parts will cost somewhere between $150 and $500 while the labor cost will be between $30 and $150. Be ready to pay some extra bucks for taxes and fees, given the laws of your local government. If you want to change it at home, be sure that you know what you are doing.