How Much Oil Can a Bad PCV Valve Burn?: You Should Not Avoid!
The PCV system helps the unburned gasses and vapors get into the intake manifold. The valve prevents gasses from reentering the crankcase and prevents oil-gas mixtures. But what if it goes bad?
How much oil can a bad PCV Valve burn?
Well, a bad PCV valve can actually burn a lot of oil. It can be a few drops of oil to an entire quart of oil. It will definitely result in oil leaks. There will also be other problems, such as clogged engines and increased fuel consumption.
The article below discusses PCV valves broadly. From identifying a faulty PCV valve to how much oil it can burn, it will cover everything. Let’s get into it!

How Much Oil can a Bad PCV Valve Burn?
When you have a faulty PCV valve, it is most likely that you will encounter oil leakage problems. How?
Because if this small piece of valve gets clogged, it won’t be able to draw enough air. The seal and gaskets will burst. And you know how much trouble oil leaks can cause.
The engine will then begin to consume more and more oil. It will start to make up for the amount it lost.
So finally, how much oil will get burned?
Well, it depends on how faulty the PCV valve is. If it’s clogged, a couple of drops of oil will probably come out.
But if it is severely damaged, then it can end up leaking almost a quart of oil. That sounds scary, right?
Well, when my PCV valve got clogged, I think I almost lost around 2 cups of oil.
That’s why you should try to prevent any kind of malfunction in the PCV valve from the very beginning.
Keep checking the PCV valve once in a while and try to change your oil regularly.
I assure you that that helps a lot. Also, see the following signs on how to identify a faulty PCV valve and take corrective measures ASAP.
6 Signs of Identifying a Bad PCV Valve
When you have a bad PCV valve, it can cause a lot of problems for the engine components. It can lead to severe damage and then you might have to pay a lot to fix them.
Here are 6 signs of a faulty PCV Valve that might need replacement:
1. Whistling Sound
You might hear one kind of whistling sound from the engine when there is a problem with the PCV valve.
Surely it can mean a lot of things, but it can be blockage in the PCV valve as well. So check it out and be sure.
2. Checking the Engine Light
This is one of the most common ways to identify a bad PCV valve.
Most of the modern vehicles have engine lights on the dashboard. If the engine light comes on don’t forget to check the valve. Wondering why?
Well, the PCV valve is directly connected with the car’s engine. So it can lead and cause different problems for the engine.
That’s why you should always have a look when the light is turned on.
3. High Idle RPM
If you continuously find the idle RPM to get high, then make sure the PCV valve is okay.
The airflow between the manifold and the crankcase is controlled by this small valve. When the PCV Valve is broken then it can cause strange idle problems for the vehicle.
That’s why if the idle RPM is really high or you are facing any kind of strange idle behaviors, you should check the PCV valve.
4. Decreased Fuel Economy
This is another common problem caused by a bad PCV valve.
When the PCV valve is bad, pressure inside the crankcase increases a lot. The oil is forced to get out. Sometimes unburned fuel enters the combustion chamber.
What will happen then?
It can lead to lowering the mileage of your favorite vehicle. This can turn out to be a big problem if you do not identify it at the right time.
As a matter of fact, it can take quite a dig at your pocket if the fuel economy isn’t dealt with.
5. Acceleration Problems
Yes, you heard it right. A faulty PCV valve can cause severe acceleration issues.
When you continue to drive with a bad valve like that, you will experience rough accelerations at low and high RPMS.
6. Smoke from the Exhaust
A faulty PCV valve could be the cause of smoke coming from the car’s exhaust pipe. The smoke is usually of three types:
- Blue
- White
- Black
Do you know why smoke will come out? Well, when you have a bad PCV valve, it forces the oil to get in the combustion chambers.
So the oil will be burning inside the engine, and you will see smoke coming out of the exhaust pipe.
Because of this, you will get blue smoke coming out of the exhaust pipe.
But if the bad PCV valve causes a lean mixture in the engine, then you will probably get white or black smoke.
No matter what the reason is, if you are getting any kind of smoke from the exhaust pipe, make sure to have a look at the PCV valve. It can cause severe problems for the entire engine.
Where is the PCV Valve?
Before you identify the faulty PCV valve or decide to replace it, you must know where the PCV valve is actually located.
Well, the PCV valve is usually located at the top of the engine on the valve corner. In most of the cars, you’ll find it there. However, you can also find it on a hose which is between the air intake filter and the valve corner.
That’s why check on top of the engine, follow the hose and you will get the PCV valve. Check this video below to get a better idea:
You will find it, there’s no doubt. But if you still cannot find it do not worry. Take it by the nearby maintenance center and they can show you right away.
Can you Drive with a Bad PCV Valve?
Yes, you can, but you should not.
A faulty PCV valve will slowly keep damaging the engine. You might not face any problems while driving the car.
And you can drive it too because you won’t face any immediate issues. You won’t certainly get yourself into accidents or something.
But if you keep on driving with a bad PCV valve, the engine will lose its efficiency. The components will be badly affected because of this.
That is why if you decide to fix the PCV valve later or have made up your mind not to replace it because of the cost, Then you’ll undoubtedly run into bigger issues.
There might be permanent damage to any of the components of the engine. It can cost you a lot more to replace or change this part than to replace the PCV valve.
My suggestion would be that if it’s not an emergency, then do not drive with a bad PCV valve. If it is totally broken, get it fixed, and then get your car on the street.
Replacement Cost of PCV Valve
You waited a while to get into this part didn’t you? Guess what, I have some good news for you.
Replacing the PCV Valve won’t cost you that much. You can get PCV Valves for around $20 to $50. Labor costs depend a lot on the location. Generally, it can start from just $30 and end up at the highest $200.
Again, if you can fix it all by yourself then you can skip the labor costs as well.
See? It is really cheap to replace the PCV Valve. That is why, if you have a broken or faulty PCV valve, don’t waste time. Spend some money and get a new one.
Frequently Asked Questions
1. When should I replace the PCV Valve?
Answer: My suggestion would be to change your PCV valve every 50000 miles. It can go bad before reaching this amount or it can even last over 100,000 miles.
But since you can get it for a cheap price, try to change it every 50000 miles.
2. What happens if the PCV valve is open?
Answer: In short, if the PCV valve is open, it will cause problems like rough running and stalling. How?
The extra air will enter the engine. There will be a bad mixture of air and fuel. So you will find several problems because of it.
3. How do you maintain a PCV Valve Properly?
Answer: Routine Cleaning.
Yap, that’s it. Try to do routine cleaning from time to time. It will keep the filters clean. Also, if you change your oil from time to time then it will help too.
4. Is a PCV valve open at idle?
Answer: No, it is not. A PCV valve should be closed or at least semi-closed while it is idle.
Final Thought
PCV valves are undoubtedly one of the most necessary car components. At the same time, a bad PCV valve can be the root of so many problems.
So, how much oil can a bad PCV valve burn? You already know.
Forget about an entire quart of oil; if you even want to save a few drops of oil, take my suggestion and change your PCV valve.
Go through the symptoms again and perform good routine maintenance promptly to keep the PCV valve in the best possible shape.
Till then, drive safe!