Oil Control Valve Functions and Malfunction Symptoms

Oil control valve is a vital part of every engine that is fitted with Variable Valve Technology. Responsible for controlling oil flow in the camshaft, it also helps in sustaining the functioning of the engine’s internal moving parts. 

In addition, there are also many other inevitable benefits of using oil control valves such as efficient fuel consumption, reducing gas emissions generated by the vehicle, and improving engine performance.

However, its failure can sometimes cause problems. Therefore, to know about the failing oil control valve symptoms, it is crucial to understand the basic functioning of it, beforehand.

Function Principle of Oil Control Valve in The Car System

This component has its own significance in any automobile smooth operation. Being regulated by the engine control module, it is also known as the engine oil solenoid valve.

This valve controls the flow of oil into the engine’s camshaft. If the oil does not reach an inappropriate amount, it may hamper the normal functionality of the engine. 

Hence, the oil control valve must open and close at the right times to lubricate the camshaft. In fact, it decides when to prevent the oil from entering or, let the oil go out. 

The PCM/ECM will control the valve and let it know about the appropriate actions based on the engine’s performance demands.

What does an oil control valve do? Let’s check out the video below for more information.

Common Failing Oil Control Valve Symptoms

There are certain symptoms, which need immediate attention for repair, and smooth functioning of the oil control valve. Some of them include:

1. Poor Fuel Economy

This means the oil control valves are unable to regulate the oil flow in the system. Thus, causing the engine to over-perform and use more oil. 

Moreover, the exhaust valves would also open and close at the wrong time, which in turn would lead to more expenditure on gas.

Eventually, it would also damage the other internal components of the engine alongside drastically reducing the fuel economy.

valve oil control
Ensure the smooth functioning of Oil control valves. (Photo: 1A Auto)

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2. Slow Acceleration

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The defect in oil usage settings would directly affect the performance of the car’s acceleration. One can check for this, by accelerating the car and noting the time taken to reach the desired speed. 

In simple words, if the car is unable to reach a 60km/h speed in a short time, then it’s a sign of disturbance in the oil control valve.

camshaft oil control valve
Keep an eye on the engine camshaft control valve. (Photo: Aliexpress)

3. Ineffective Engine

For ensuring the flawless and superlative oil control valve, one must consider the variable valve timing system of the car. 

It generates the power required by the vehicle, which activates automatically when the RPM is higher than the normal. Even when the load on the car is more, especially on the upper hill road, it stimulates.

In this regard, if the Variable Valve Timing (VVT) Solenoid is impaired, it can bring fluctuation in the revolutions thus, reducing the power of the vehicle.

Now, the question arises why this happens? Well, the main cause of damaged oil control valve is not replacing the oil timely. This negligence can cause impurity, leading to blockage and subsequently, preventing the oil from entering into the camshaft.

Now, it must be easier to detect the malfunctioning of the vehicle and work on its maintenance tips in order to prevent the large expenses.

4. Overheating Engine

Keep in mind that the oil control valve does more than only regulate pressurized motor oil to adjust the camshafts’ position and angle. 

Fresh oil is pumped through the valves, camshafts, solenoids, and many other component elements of a variable valve timing system when the oil control valves open.

oil regulator valve
The oil control valve does more than only regulate pressurized motor oil. (Photo: RAC)

By directing heat from these components into the oil pan, where it may be cooled, this creates a supplementary type of cooling (in addition to the coolant). 

If and when the oil control valves malfunction, it may prevent oil from getting to these parts, raising the temperature of the engine and increasing component wear.

5. Rough Idle

Under typical circumstances, the VVT system operates at higher RPMs or while under stress, such as going up a hill.

Excess engine oil may be injected into the VVT system by a defective oil control valve or VVT solenoid, resulting in rough idling, stalling, or just poor engine performance in general.

6. Check Engine Light on

The check engine light will invariably illuminate if there is something wrong with the oil control valve. The onboard diagnostic system (OBD2) will generate a code. 

This code will tell you whether the issues you’re experiencing are due to the OCV and its associated VVT solenoid. DTC P0008, P0014, and P0017 are all VVT-related codes.

As with all Check engine light ‘on’ occurrences, the car can be driven for a limited distance before being towed to a service specialist for repair.

engine oil pressure control solenoid valve
The check engine light will illuminate if there is something wrong with the oil control valve. (Photo: Edmunds)

What Are Causes For A Bad Oil Control Valve?

As instructed by the ECU, the VVT solenoid is electrically powered. The VVT solenoid might stop working if there is a problem with this system or its electrical wiring. 

Additionally, the solenoid itself may experience an internal electrical problem and start to function only occasionally or not at all.

The OCV uses engine oil, which must be clean to operate properly. Sludge and/or varnishes (sticky deposits) may accumulate in this valve if regular oil and filter changes are not carried out as instructed in your owner’s handbook.

This pollution may delay or prevent its operation. Furthermore, despite the fact that this valve is quite basic, an internal mechanical breakdown might lead it to fail to work.

An inline oil screen before the valve oil input is used in many OCV setups. Dirt or sludge might partially or totally obstruct this screen. This obstruction can obstruct flow to the OCV, causing it to fail to work.

Again, clean oil is essential. Engine oil and filter replacements on a regular basis can help prevent this sort of failure.

Can You Replace A Faulty Oil Control Valve?

The mere answer is yes, but you must be knowledgeable in this field. Changing the oil control valve yourself can lower the overall cost if you are confident working with motors and are capable of conducting the necessary web study to educate yourself.

To guarantee that the engine has clean oil and that any sludge has been removed, be prepared to replace the oil and filter at the same time. For the majority of automobile owners, hiring a qualified technician is preferable.

They are equipped to identify the problem by reading the ECM error codes. They may also change the motor oil and filter at the same time as replacing the VVT solenoid if that is necessary.

Watch the video below to know how to replace oil control valve in Toyota cars!

What Does It Cost For A Faulty Oil Control Valve Replacement?

What can you do to remedy a malfunctioning oil control valve now that you know what to look for? Unfortunately, an oil control valve cannot be simply repaired; instead, a complete replacement is advised. 

Additionally, and in some vehicles, the oil control valve and VVT solenoid are combined into a single device. In that situation, replacing the OCV also necessitates replacing the complete VVT solenoid.

A malfunctioning oil control valve will set you back between $100 and $600 to replace. When broken down, oil control valves (with a VVT solenoid) range in price from $50 to $300. 

Labor charges will raise the total cost by an additional $50 to $300. The cost of replacement will often range from $200 to $500, however it will depend greatly on the brand and model of your car.

oil control valve solenoid
If your car has to use premium or specialized oil control valves, the cost of the necessary parts would go up. (Photo: Auto Chimps)

Additionally, if your oil control valves are challenging to reach, the labor cost may be greater. In addition to replacing the OCV and VVT solenoids, the following expenses should be considered:

  • Diagnostics ($50 to $150) – Charged by a mechanic to diagnose and pinpoint the current problem (not always relevant). This frequently covers the expense of scanning for error codes and evaluating the OCV.
  • Oil change and filter replacement ($40 – $150) – If the OCV failed due to burnt-out, polluted, or old oil, wash it out as well. Then, add new oil to your automobile and replace the oil filter. This will aid in the removal of sludge from the oiling system.

FAQs on Oil Control Valve

  1. Can you drive a car with a faulty OCV?

Even if your car’s VVT solenoid is broken, you could still drive it, but it won’t be fun. This failure can result in a variety of operating problems, such as a rough idle or slow acceleration, depending on the circumstances. 

Regardless of the symptoms, the engine will not function at its best, significantly increasing fuel consumption. Unattended VVT faults may eventually do further harm to the engine.

  1. Can engine knock be caused by poor oil control valves?

Yes. If one or both of the engine’s VVT solenoids or OCV malfunction, the engine can start to bang and ping. 

If a VVT issue causes the air/fuel mixture to get so lean that it pre-ignites during combustion, this will take place. If your car’s engine is banging, you shouldn’t drive since pre-ignition may be quite harmful.

  1. How long do VVT solenoids and oil control valves last?

The level of valve production and maintenance affects the oil control valve or VVT solenoid service life. The oil control valve typically lasts between one and three years.

Hopefully with this article, you will get a deep knowledge about oil control valve, what does an oil control do and its bad symptoms. 

If you have any question about the topic or any car question, feel free to leave us a comment below, our auto experts will answer it for you.