You’ve probably heard about the PCV valve of a gasoline or gas engine, but you may not have heard of how important this little engine component is.
Usually, PCV valve problems are faced by drivers who own cars with gasoline engines, and the valves are made of plastic hoses that have an inner spring.
It is natural for these valves to give way at a certain time, because any plastic material that is mounted in a place with high temperatures, gives way after a certain time.
Well, in the following article you will find out more details about the PCV valve and you will discover what are the clear signs that the PCV valve is faulty or that it is going to malfunction.
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1. Check-Engine light
One of the most common problems when it comes to PCV valve failure is characterized by the ignition of the engine warning light in the dashboard of the car.
When the warning light comes on board, it is clear that an error code has been stored in the engine control mode, and it is necessary to use the OBD2 scanner to detect it. But there are also old cars that do not have an on-board computer, and they will not display this issue.
2. High Idle
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Given that the PCV valve has the role of controlling the flow of air between the crankcase and the intake manifold, in conditions where it is defective, there may be the same symptoms as when the intake air leaks, which leads to increased airflow causing the idle revs to fail. If you experience such symptoms, you might want to check the PCV before anything else
3. Air gas mixture too rich
Due to the details mentioned above, it should be noted that a PCV valve can have the same symptoms as the intake leak, so the air-fuel mixture can be wrong. Most of the time the air-fuel mixture can become weaker than necessary.
4. Engine misfires
Due to the fact that an improper mixture can be reached due to the broken PCV valve, you may feel missed when the car is idling, or during acceleration.
In case of a weaker mixture than necessary, the cylinders will not ignite correctly, and this leads to misfires, while if the mixture is too rich the fuel spark can be stopped, so this is again a reason why the misfires can make an appearance.
5. Heavy acceleration
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Also due to an improper mixture, you can feel a heavier acceleration of the car at both low and high speeds.
Most of the time you don’t feel the broken PCV valve at high speeds, but at idle speeds you will notice it, but here everything depends a lot on its design.
6. Increased oil consumption and oil leaks
If the PCV valve or hoses are blocked due to moisture, high pressure is reached in the engine chamber, which will cause it to push up into the cylinders, and exit through the gaskets. If you ever notice large oil leaks and engine oil consumption, it is necessary to check the PCV valve and hoses to see if they are blocked.
7. Black and white-blue smoke from the exhaust
If the PCV valve or hoses are blocked, the oil pushed by the crankcase will reach the combustion chamber, which is why the oil will burn inside the engine. As a consequence of this we will see blue some coming out from the car’s exhaust pipe
If the PCV valve is broken and causes a poor mixture or a rich mixture in the engine, you can get black smoke removed from the car exhaust or even white smoke, depending on the type of mixture that the car engine has.
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As a conclusion for this sub-point we can say that in the conditions in which the smoke has a color between the three mentioned above, you must check the PCV valve as soon as possible.
What is a PCV valve?
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This valve is located in a vertical position and is important in terms of positive ventilation of the crankcase and is considered to be a very old emission device, used in the case of a very large number of cars.
The role of the PCV valve is to eliminate the emissions of the crankcase from the engine, which it will transfer to the intake system, so that it will burn them once again in another engine cycle, making the emissions more efficient and cleaner. This way, the car will not pollute the environment too much.
The manufacturing method of PCV valves is usually the same, and both are equipped with two pressure connectors that have a spring valve inside. When stationary, there is a vacuum inside the intake manifold, which helps eliminate emissions from the crankcase at low speeds.
When the engine is running or driving at higher speeds, the PCV valve opens and sucks more crankcase ventilation which is caused by the running pressure, but also by the increase in crankcase pressure.
The lowest RPM values are high vacuum, PCV valve half closed. The highest values of the RPM are the lower vacuum and the fully open PCV valve, while the crankcase failure is represented by the closing of the PCV valve.
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Given that the car’s engine is equipped with a turbocharger, then it is certainly not advisable to increase the pressure to enter the crankcase because in this way the oil will leak and the gaskets will be sealed.A car like that requires a one-way PCV valve, which is built differently from ordinary valves given that it operates only on low or inactive RPMs.
There are such valves that are equipped with 3 vacuum connectors, and the valves have control over them by means of electric vacuum solenoids, which have several modes of operation.
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How often should the PCV valve be replaced?
There is nowhere specified the time interval at which this component must be changed. If the valve is made of plastic, it wears out because the valve is found in very hot places, and inside the hoses there is a large amount of fuel - oil permanently. For this reason, the valve or hoses may fail sooner or later.
If you buy a used car, it is advisable to replace the valve as soon as possible, if you do not know when it was last replaced.
It is recommended that when you go by car to the service to ask for the hoses that are found around the PCV valves, and if they are cracked or not in a good condition, you must change them as soon as possible , because the chances and the PCV valve to be in such a state are very large.
These valves and hoses have very attractive prices and are simple, fast and easy to change, so rather than complicating things, it is better to change them in time.
Where is the PCV valve located?
The answer to this question depends on the case and from car to car. In the case of an old car that does not have a turbo, it is possible that the PCV valve can be found either at the top or on the side of the valve cover. Most of the time the valve is found on the valve cover on the car.
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In case you don’t know, the PCV valve can be mounted between the inlet and the valve cover, and if you can’t find it, it’s important to check the hoses that move from the valve cover to the intake system, because that’s where the valve is. .
If we are talking about newer cars that have turbo, the PCV valve is found inside the hose and is very difficult to detect. We are talking here about models such as Audi, Skoda, Volkswagen or Seat that have a 1.8 engine. Here the valve is located under the inlet inside the hose and can be complicated to detect.
How to check if the PCV valve is disconnected?
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In order to detect if the PCV valve is disconnected or not, different operations can be performed, and here we can give as an example the visual verification of it, or its removal from the car all together. In the following you will find out how to check the PCV valve quickly and efficiently.
Open the oil cover when the car engine is running. This way you can detect a possible failure of the PCV valve without removing it. Therefore, start the engine and leave it running, then remove the oil cover. If you feel that it is being sucked into the engine, it is difficult to remove it because there is too much vacuum inside the valve, which more than likely means that the PCV valve is defective.
If when you remove the oil cap and it feels like it is about to explode, it means that the pressure is very high and is caused by a malfunction of the PCV valve, but this high pressure can also be caused by other factors such as wear of the piston rings. , but first you need to check the PCV valve.
When the car’s engine is started, it is advisable to spray a flammable spray near the inlet, because this way you will find out if there are leaks near the PCV valve or around the hoses.
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If the engine is running the moment you spray that spray, and it is obvious that there is a leak near the place where you sprayed, you need to disconnect the valve and hoses and try to see if you can find the place. through which leakage occurs.
It is extremely important to know that this method is extremely dangerous, and if you are not careful, a fire can break out, so if you still decide to take this step, you need to have a fire extinguisher close by
1. Visually check the PCV valve and spring
If you feel too much pressure or too much vacuum inside the PCV valve, then it is necessary to remove and check the PCV valve to find out if there is any defect.
2. Check the hoses for moisture
If there is too much pressure inside the engine, oil leaks or blue smoke comes out of the car’s exhaust . Under these conditions it is necessary to check if there is moisture inside the PCV valve and inside the hoses.
How can the problem be diagnosed and how can the PCV valve be tested?
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Why do certain PCV valves heat up?
Inside the PCV valve and inside the hoses there may be condensation, moisture or other liquids that have a very bad smell. If condensation is found inside them, then it can freeze at low air temperatures.
If you’re wondering what this means, well, a frozen hose completely blocks the flow, which leads to serious engine problems due to the fact that the pressure will increase enormously inside the crankcase.
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Increased crankcase pressure leads to oil consumption and oil leaks, and this will cause problems such as oil pressure and blown engine seals.
Common PCV valve trouble codes
It is worth mentioning that there are some codes that appear when the PCV valve is malfunctioning , and in the following we will present them for you to know. P052E is the first code you need to know and is related to the performance of the crankcase positive ventilation regulator valve.
P0171 is the second important code you need to know about, and it refers to the fuel system . Regarding the detection of random or multiple cylinder errors, the code P0300 must be mentioned, while for the control circuit regarding the positive ventilation heater of the open crankcase we mention the code P053A.
The costs that you have to endure if you have a defective PCV valve, depend a lot depending on the manufacturer and model of the car. It is worth mentioning that we are talking about cheap parts compared to other components, so you do not have to worry about buying a PCV valve.
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If you consider that you are ready to personally replace the PCV valve, you will not have to pay for the labor costs, and thus you will save some money. If you do not have knowledge in the automotive field and consider that you can’t manage it you can drive to an authorized service, and our bill is going to depend on the manufacturer and model of the car.
When it is necessary to remove the intake system to have access to the PCV valve, it is more work, and the price will be higher.
In conclusion, we can say that if you detect problems with fuel consumption at idle or if you discover problems with oil consumption, you must perform a check of the PCV valve, which is usually found on the crankcase in the case of old cars.
Fortunately, these valves are attractively priced, so financially you have nothing to worry about. However, replacing these valves can take more or less time, depending on the make and model of the car, but also depending on the age of the car and depending on your skill or that of the car mechanic.
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Photo source: grimmermotors.co.nz, carhowto.com, bavarian-auto.com, youtube.com, eeuroparts.com, flickr.com, outilsobdfacile.com