Can An EVAP Leak Cause Transmission Problems?

Is your car’s transmission giving you trouble? It could be the result of an EVAP leak! Find out how to diagnose and repair issues with the evaporative emission control system.

The Evaporative emission control system(EVAP) helps prevent the release of fuel vapors from escaping into the atmosphere.

But can an EVAP leak cause transmission problems? Yes, EVAP leaks can cause transmission issues. The teeth of the gears should properly grip for running the engine efficiently.

Whenever there is a leakage, the fuel vapors start to enter the vehicle’s transmission system and can make the gears slide, which is dangerous.

It can occur anytime, i.e., whenever you park your car or drive on the road. Driving with slip gears will damage the internal components badly.

The engine will start to lose power, or you will experience rough idling because of such a region.

Can An EVAP Leak Cause Transmission Problems

What Is Evaporative Emission Control System?

The gasoline in the fuel tank and fuel lines tends to evaporate with time.

These fuel vapors comprise hydrocarbon, benzene, and lead that react with air to form smog and ground-level ozone, which is harmful to humans.

So, the Environmental Protection Agency has mandated that all new vehicles must be equipped with an Evaporative emission control system

The main work of this system is to prevent the release of hydrocarbon carbons from escaping into the atmosphere and thus prevent air pollution.

Now let’s discuss its working principle.

The Evaporative emission control system comprises of few components like a fuel tank, fuel line, charcoal canister, vent control valve, purge valve, and liquid-vapor separator.

When the gasoline evaporates in the fuel tank, the excess vapors move to the EVAP canister.

The canister has activated charcoal which helps store the gasoline vapor until the purge valve opens.

The ECM entirely controls the EVAP system. It directs when to open the purge valve and directs the fuel vapors inside the engine.

The function of the purge valve is to move the fuel vapors from the canister to the engine intake manifold so that it will burn along with fresh air and help produce power.

The faulty purge valve can create a vacuum leak, which can cause low mileage, and engine problems. It will even start to circulate either too little or too much fuel inside the engine.

What Are The Reasons For Evaporative Leakage?

  • Leakage in purge valve solenoid shift.
  • Leakage in hoses of the EVAP
  • The cap of the fuel tank is loose or missing
  • You have used an improper cap in the fuel tank
  • Leakage in the fuel tank

What Are The Signs Of Evaporative Emission Control SystemLeakage?

Whenever there is a leakage in the Evaporative Emission Control system(EVAP), you will first notice that your check engine light will trigger on the dashboard.

But there are more than 1,400 reasons why the check engine light becomes activated. So, it becomes difficult for someone to pinpoint the exact reason.

Well, the other symptoms of a leaking EVAP System are as follows

  • The gasoline smell comes from your car engine
  • Engin stalls
  • Reduction in power
  • Low gas mileage
  • The engine will run lean
  • Misfiring of cylinder

What Should You Do To Diagnose Leakage In The EVAP System?

When the EVAP system starts to leak, then it causes the harmful gasoline vapors to release directly into the atmosphere.

These hydrocarbon vapors will react with nitrous oxide and cause severe air pollution.

Breathing such harmful gases can cause vomiting, and headache and, in the worst cases, harms your internal organs like the heart and lungs.

So, you need to find the exact cause behind the faulty EVAP system.

#1. Check The Gas Cap

Check the gas cap thoroughly. If it is damaged, missing, or has cracks, there will be a leakage in the EVAP system.

Sometimes the gas cap can be rusted with time, resulting in leakage. If this is the case, you must replace it with a new cap.

#2. Check For Cracks

There can be cracks in the hoses of the EVAP system, which can cause leakage. So you can check the hoses thoroughly.

If you cannot trace it, take your vehicle to the repair shop for thorough checking and, if required, replace the hoses.

#3. Faulty Purge Valve

Sometimes the purge valve can become dirty with time as it handles fuel vapors which can comprise dust, dirt, and other debris. Hence it can cause leakage.

Frequently Asked Questions

#1. What problems can an EVAP leak cause?

There are some issues that an EVAP leak can cause. We are listing them below
Engine stalls or becomes hard for you to start the engine
Reduction in gas mileage
The vehicle will not accelerate properly
The engine will smell like gasoline as there will be leakage of many fuel vapors.

#2. What happens if you drive with an EVAP leak

Driving with an EVAP leak will not immediately affect your drive.
But it will start to release harmful gasoline vapors directly into the atmosphere and create air pollution, which is harmful to our health.
If you continuously drive for many miles with EVAP leakage, gasoline vapors can start to enter the transmission system, for which gears may lose their grip.
As a result, you will experience rough idling, or the engine may begin to lose power.

#3. How serious is an evaporative emission system leak?

The Evaporative emission control system will immediately not affect your drive. But releasing harmful hydrocarbon vapors will cause air pollution.
Additionally, toxic vapors may seep into the car cabin, and you will start inhaling these gases without knowing.
Inhaling poisonous gases for a long time can create breathing problems, headaches, and vomiting.

#4. How much does it cost to fix an evaporative emissions leak?

You need to pay approximately $600 to fix evaporative emission leakage.
The price mainly depends on the type of leakage or fault in any evaporation emission control system component.
If you have an OBD 2 code reader, you can easily detect the exact reason for leakage and solve the problem.
But we recommend you always take your vehicle to the mechanic, who will help eliminate the problem.

Wrap Up

An evaporative emission control system is quite an essential part of your vehicle.

It helps to reduce air pollution by preventing harmful fuel vapors from being directly released into the atmosphere.

But leakage in the system can create issues like transmission problems and enhance air pollution. So, it’s better to detect the leakage as soon as possible and fix it.

Thank you for reading this article!

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Sean Mendez

Hi, I am Sean, a self-confessed petrolhead. I live in Boise, Idaho with a busy family of four and our energetic Labrador retriever. Thank you for visiting my website. You can find my email on the contact page.

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