Can a bad PCV valve cause misfire

Can a bad PCV valve cause misfire 

We know that you probably don’t realize how important your PCV system is. PCV stands for Positive Crankcase Ventilation, but what exactly does that mean? Your car’s PCV valve is a one-way valve attached to the crankcase that holds motor oil and produces gasses when your engine burns fuel its meant for the well-being of your engine.

Note that a bad PCV valve or its related component can produce a number of symptoms. Take, for instance, if the valve clogs, or gets stuck in the closed position, you will observe one of these symptoms.

Remember that most of the PCV valves are made of plastic hoses with a spring inside. Just as you know, any plastic would wear out after 10 years of been mounted in a hot place like your engine bay. However, because of the importance of the PCV valve; you will observe various symptoms from it when it fails.

why is the PCV Valve so Important

Any bad PCV valves can cause an engine oil contamination, and sludge build-up. It can also cause oil leaks, high fuel consumption, and other engine-damaging problems, depending on the type of failure.

With a simple inspection, you can detect some of these problems before they escalate. A failure in the PCV valve or related components often results in an expensive repair. This is because most car owners don’t include the PCV system in their maintenance routine.

Irrespective of car manufacturers suggesting replacing the valve at regular basis, car owners still forget to replace it. However, not all manufacturers stress the importance of regular system inspections.

As a lot of people keep asking, can a bad PCV valve cause misfire? In today’s article, we will answer this question and show you the symptoms of a bad PCV valve.

However, before we get to that, here’s what the PCV valve does, what happens when it fails.

 HOW PCV WORK 

Immediately after each combustion process, the exhaust valve routes these gases into the exhaust system. This is where the catalytic converter turns them into much less toxic fumes before releasing them into the atmosphere.

Also, a small amount of the gases in the combustion chambers find its way into the crankcase, by the way of pressure leak between the piston rings and the cylinder wall.

If left on their own, these vapors and fumes will cause problems with your engine. The blow-by gases contain hydrocarbons (unburned fuel), sulfur, carbon monoxide (partially burned fuel), acid, water, and particles.

 

SYMPTOMS OF A BAD PCV VALVE

As you now know that the PCV valve is very important for the engine to run properly, you probably understand that there are a lot of different symptoms associated with the PCV valve. Here are the most common symptoms when it comes to a failed PCV valve.

  • The Check Engine Light

One of the common problems when it comes to a bad PCV valve on modern cars is the check engine light flashing on your dashboard. Whenever the engine light is showing up, then there is a trouble code stored in the engine control module. And to read this trouble code from the engine control unit, you have to make use of an OBD2 scanner. Though some older cars with a PCV valve fitted without an electronically controlled engine will not have this symptom.

  • A Higher Idle RPM/Rough Idle

Since the PCV valve is controlling the air that flows between the crankcase and the intake manifold, then a broken PCV valve can have the same symptoms as an intake air leak. This can cause the idle RPM to get too high and other strange idle behaviors like a very rough idle. In case you have any strange idle problems, it’s always a good idea to examine the PCV valve first.

  • A Lean/Rich Mixture

A bad PCV valve can have the same signs as an intake leak, and the air/fuel mixture can end up being wrong. But in most cases, the air/fuel mixture will become lean and you’ll feel the same symptoms as a lean mixture.

  • Engine Misfires

Just as you can get a faulty lean/rich mixture because of a bad PCV valve, you can feel misfires on both idle or acceleration when your PCV valve is bad. In case you have a mixture that is lean, the cylinders won’t fire up correctly and this can cause misfires. But in case you have a mixture that is too rich, you can turn off the spark with the fuel and therefore causing engine misfire.Denso Iridium Spark Plugshttps://kctimoauto.com/product-category/engine-parts/sump-pans-plugs/

  • A Rough Acceleration

Sometimes, you can feel that your car has rough acceleration both on high and low RPM’s. In some cars, you won’t feel a broken PCV valve on high RPM’s than idle, but this can happen depending on the design of the valve.

  • An Increased Oil Consumption & Oil leaks

This will push the pressure up in the cylinders and out from the gaskets. And in case you notice several large oil leaks and increased oil consumption in your car, examine the PCV valve.

  • A White/Black/Blue Smoke from the Exhaust

This will cause the oil to burn inside the engine and go out through the exhaust pipe. Also, it will cause a lot of blue smoke from the exhaust pipe.

But if the PCV valve is bad and causes a rich or lean mixture to the engine, you can get symptoms like white or black smoke coming out from the exhaust pipe. Though this depends on what type of mixture problem the engine has. However, if you notice any strange smoke from the exhaust pipe, ensure that the PCV valve is in good shape.

 

Conclusion on your question, can a bad PCV valve cause misfire?

As you can see, a bad PCV can cause engine misfire and some other symptoms. So if you experience any strange problems on idle or an increased oil consumption, then examine your PCV valve. Your car PCV valves are often located on the crankcase cover on older vehicles.