8 Warning Signs of a Bad PCV Valve

Summary

Your car’s pressure and airflow are regulated by the positive crankcase ventilation valve or PCV valve. While it is a part that is frequently forgotten during regular service, your car will run differently if the PCV valve is not working fine.

When your car’s PCV valve goes faulty or the hoses that feed the system get clogged, you’ll experience different warning signs The major one is the reduction in engine performance.

You’ll also not notice the following signs of a bad PCV valve: engine noises, check engine light, misfiring while idling, oil spills, high fuel efficiency, black exhaust smoke, and rough acceleration.

Fortunately, the PCV valve is neither expensive nor difficult to test, clean, and replace. Changing or servicing this component won’t cost you much.

Let’s go deep to explain the 8 warning signs or symptoms of a bad PCV valve!

Engine Noises

While driving, strange noises are a sure sign that something isn’t working properly. A hissing, whistling, or whining sound coming from the engine, and occasionally a deep moaning murmur, is one of the most typical signs of a faulty PCV valve.

A leak in the PVC hose is most likely to be blamed for the hissing sound.

Check Engine Light

A faulty PCV valve is one of the possible causes of the Check Engine Light appearing on your dashboard because it works directly with your engine.

Keep in mind that if you drive an older model car, the PCV system may not have been installed if your engine was electronically controlled; as a result, a faulty PCV valve won’t turn on your check engine light.

The engine control unit (ECU) stores a fault code that activates when the engine light appears. You’ll need an OBD-II scanner or code reader to read the engine control unit’s fault code to determine the precise issue with your PCV system.

Misfiring While Idling

A misfire will sound like the engine is vibrating, which is a surefire symptom that the engine is not running at its best. Typically, when a situation like this arises, the car is idling.

Vacuum leaks, particularly one-cylinder-confined ones that let more air into the affected cylinder and disrupt the ideal air and fuel mixture, are the cause of engine misfiring.

Rough Idle

A faulty or broken PCV valve might present itself in the same way as an intake air leak because it regulates the flow of blow-by-gasses from the crankcase to the intake manifold.

A defective PCV valve can result in excessive idle RPMs and odd idle behaviors, such as extremely rough idling.

Oil Spills

The pressure inside the engine crankcase will rise if the PCV valve or the hoses are blocked, and since there is no other route for the pressure to be released, the oil in the cylinders will be forced out through the seals and gaskets.

Inspect the PCV valve and the hoses going to the valve to make sure they aren’t blocked if you suddenly discover many sizable oil puddles passing into the floor of your garage (upon inspection, oil is leaking through the seals).

Poor Fuel Efficiency

The correct air and fuel ratio mixture, which is necessary for ideal combustion, will be thrown off by a broken PCV valve. This is because the vacuum on the cylinder head’s intake side will be unable to accurately estimate how much fuel should be injected into the cylinder for combustion.

Black Exhaust Smoke

The increased crankcase pressure will force engine oil into the combustion chambers, where it will be burned and escape through the exhaust pipe if the PCV valve or the hoses connecting to it are blocked.

Your tailpipe will emit a lot of blue smoke if you are burning oil.

Rough Acceleration

When the air and fuel mixture provided to the engine is thrown off by a faulty PCV valve, you may experience jerky acceleration at both high and low RPMs.

On most cars, this scenario will be less noticeable at higher RPMs than it is at idle, but depending on the PCV valve’s design, it may still occur.

Bottom Line

To keep your engine running at its best, you must be aware of the signs of a faulty PCV valve. Symptoms such as an engine light, high oil consumption, or decreased fuel economy can assist you in recognizing problems early on and preventing harm to the engine.

That is all for the article, where the symptoms of bad or faulty PCV valve is discussed. I hope it was helpful, if so, kindly share with others. Thanks for reading, see you around!