Symptoms of a Bad Oil Control Valve – VVT Solenoid

Variable valve timing (VVT) solenoid, also referred to as the oil control valve (OCV), is one of the most important parts of the vehicle. Its utilization in the latest vehicle models aims to enhance fuel efficiency and performance by modifying the valve lift process. This article explains the bad VVT solenoid symptoms, causes, and how to replace it.

What is the function of the Oil Control Valve?

The oil control valve (OCV) controls the oil flow to various engine parts, such as the variable valve timing systems, camshafts, and other hydraulic systems, according to the engine load and speed. VVT solenoid is an important part of the variable valve timing system.

VVT solenoid. oil control valve

In engines equipped with VVT systems, the OCV plays a crucial role in regulating the timing of the exhaust and intake valves.

By regulating the oil flow to the camshaft phasers or other VVT parts, the oil control valve may retard or advance the valve timing.

The oil control valve possesses multiple crucial functions, which encompass optimizing fuel consumption, mitigating vehicle emissions, and enhancing overall engine performance.

Bad Oil Control Valve Symptoms

A bad oil control valve or VVT solenoid produces one or more of the below-given symptoms:

  • Poor Fuel Economy
  • Check Engine Light Illumination
  • Rough Engine Idle
  • Poor Engine Performance
  • Rough Acceleration
  • Engine Knock
  • Increased Oil Consumption

1) Poor Fuel Economy

One of the clearest signs of a malfunctioning VVT solenoid is a decrease in fuel efficiency. The primary role of the VVT solenoid is to optimize engine functioning and improve fuel economy by precisely timing the opening and closing of the inlet and exhaust valves.

Poor Fuel Economy

A faulty VVT solenoid or oil control valve may affect the entire system, leading to the wrong operation of the intake and exhaust valves. This typically results in a significant decline in fuel economy.  

2) Check Engine Light Illumination

The latest vehicle models have an engine control module (ECM) that plays a crucial role in monitoring and detecting any irregularities within the vehicle. This is done through the check engine light, which illuminates when any ongoing activity deviates from the predefined values.

Reset Check Engine Light

The ECM of your vehicle constantly monitors the performance of various parts. When the VVT solenoid is not functioning correctly, your ECM triggers the check engine light on the dashboard, signaling a potential issue.

Read More: How to reset Check Engine Light

3) Rough Engine Idle

Maintaining proper ignition timing is vital to ensure a smooth and effective engine operation. Under load conditions, the VVT solenoid of your vehicle monitors the engine and transfers data to the vehicle’s main computer to make necessary adjustments to the valve timing.

Engine Idle, symptoms of bad VVT solenoid

But as your solenoid stops functioning correctly, it doesn’t send accurate data to the computer. Although the solenoid is designed to operate mainly under non-standard driving conditions, it may lead to the rough performance of the engine.

If you observe a rough idle, particularly if the engine RPM fluctuates between 100 and 300 RPM at idle, it is advisable to promptly seek assistance from a mechanic.

Read More: Why Car Shakes at Idle?

4) Poor Engine Performance

Poor engine performance is one of the clear symptoms of a bad oil control valve.

poor engine Performance

The VVT solenoid is designed to enhance engine power at higher RPMs while maintaining a consistent engine performance at lower RPMs.

Consequently, a defective solenoid may lead to a significant decrease in performance if it fails to advance the camshaft timing while accelerating.

5) Rough Acceleration

The primary function of the VVT solenoid is to alter the timing of the camshaft, ensuring smooth and efficient engine operation across various engine RPMs. However, if this solenoid fails, it can lead to rough acceleration and even misfire during acceleration.

Rough Acceleration

If you experience rough acceleration accompanied by the check engine light illuminating on your dashboard, it is highly probable that a bad VVT valve is the cause of these issues.

6) Engine Knock

Your engine starts producing knocking when the combustion of fuel happens before the spark plug burns the air/fuel mixture. This premature ignition, which deviates from the premeditated timing by the ECM, can result in higher fuel consumption, poor engine performance, and potential engine damage if severe.

Engine Knock, signs of bad oil control valve

A malfunctioning oil control valve may contribute to engine knock if the camshaft phase remains stuck in an aggressive position, leading to incorrect timing of valve opening and closing. This may also lead to misfires, where the air/fuel mixture ignites poorly or doesn’t ignite at all.

7) Increased Oil Consumption

Increased Oil Consumption

If the oil control valve or VVT solenoid of your car is not working efficiently, it may cause poor oil flow and distribution within the engine. This may lead to increased oil consumption as the engine parts may not get sufficient lubrication, leading to accelerated wear and potentially causing other issues.

Read More: Oil Color Chart

Causes of a bad VVT Solenoid

A VVT solenoid may go bad due to one or more of the following causes:

  • Insufficient Engine Oil
  • Dirty Engine Oil
  • Wear and Tear
  • Engine Overheating
  • Manufacturer Defect

1) Insufficient Engine Oil

Maintaining a sufficient level of engine oil is crucial to prevent issues with the oil VVT solenoid. Failure to do so can lead to various problems.

Therefore, it is vital to adhere to the manufacturer’s suggested engine oil change intervals to prevent such situations. Additionally, inadequate engine oil may also affect other engine components and sensors, such as the crankshaft position sensor, MAF sensor, O2 sensor, and MAP sensor.

Read More: Low Oil Pressure Symptoms and Causes

2) Dirty Engine Oil

For optimal performance of the VVT solenoid, it is essential that the engine oil remains clean, devoid of debris, and retains its proper viscosity and lubricating properties.

When engine oil becomes contaminated with solid particles, debris, or dirt, it can clog the channels from the solenoid to the VVT chain and gear. Failure to change the engine oil as per the recommended schedule may result in damage to the gear drive, VVT chain, and VVT solenoid. 

3) Wear and Tear

Your VVT solenoid may experience normal wear and tear over time, leading to internal degradation or mechanical failure. Continuous use, exposure to high temperatures, and other factors may lead to this wear.

4) Engine Overheating

Overheating of the engine can also lead to the failure of the VVT solenoid. Engine overheating can be caused by various factors, including a blown head gasket, a malfunctioning radiator, or insufficient coolant.

To preserve the health of the VVT solenoid, it is crucial to address any issues related to engine overheating promptly.

Read More: Causes and Symptoms of Engine Overheating

5) Manufacturer Defect

In some cases, a VVT solenoid may have a manufacturing defect that causes premature failure or malfunction. This could be due to poor-quality materials, design flaws, or other production issues.

VVT Solenoid Location

The VVT solenoid of your vehicle is typically located in the cylinder head near the camshaft. It is commonly found on the intake side of the engine, as many car models only have the VVT solenoid fitted on the intake camshaft. However, certain vehicles may feature two VVT solenoids, with the second one located on the exhaust camshaft.  

VVT Solenoid Location

In a few vehicles, the VVT solenoid is installed on the valve cover’s interior. This particular placement can make it more challenging to access and perform maintenance or repairs on the solenoid.

VVT Solenoid Replacement Cost

The replacement cost of the VVT solenoid depends on your vehicle’s make and model. The average replacement cost of the VVT solenoid is from $120 to $540. The labor costs from $60 to $280, and the part itself costs from $60 to 260.

How to Test a VVT Solenoid 

FAQ Section

Can I drive with a bad VVT solenoid?

Driving a vehicle with a faulty VVT solenoid can result in an unpleasant experience and various running issues. Depending on the specific situation, these failures can lead to symptoms like poor acceleration or rough idle. The engine will not operate efficiently, leading to significantly increased fuel consumption. Ignoring VVT issues over time may also result in many other engine problems.

What is the function of VVT Solenoid?

The function of a VVT solenoid is to regulate and control the oil flow to the VVT actuator, which in turn adjusts the timing of the camshaft in an engine equipped with variable valve timing (VVT) technology. This allows for optimal performance, fuel efficiency, and power delivery across different engine operating conditions.

Can a bad VVT solenoid cause a misfire?

Yes, a faulty VVT solenoid may lead to misfires. The primary role of the VVT solenoid is to control the timing of the camshaft, ensuring optimal engine performance across different RPMs. If the VVT solenoid goes bad, it can lead to rough acceleration and potentially cause misfires during acceleration.

Can a bad VVT cause engine knock?

Yes, the engine may experience knocking and pinging if one or both of the VVT solenoids don’t work. This happens when a faulty VVT disrupts the air-fuel mixture, causing it to become too lean. As a consequence, pre-ignition can occur during combustion. It is crucial to avoid driving a vehicle with a knocking engine, as pre-ignition can cause significant damage.

Does low oil affect the VVT system?

If the engine oil in your car is insufficient, its oil quality is poor, or it hasn’t been replaced for an extended period, there is a high likelihood of experiencing a malfunction in the VVT system. The VVT system operates as a hydro-mechanical system that depends on the presence of pressurized oil. Even a minor variation in oil pressure or flow can disrupt the proper functioning of the VVT solenoid.

What happens when the VVT solenoid goes bad?

When the VVT solenoid malfunctions, it may hinder the advancement or retardation of valve timing as required. Consequently, your engine may face performance issues such as poor acceleration, rough idle, poor fuel economy, or reduced overall engine performance.

What does a bad VVT solenoid sound like?

When the VVT solenoid goes bad, it can impede the flow of oil pressure to the VVT actuator. This can result in noticeable engine noises, such as ticking or rattling sounds.

Does the VVT solenoid affect idle?

VVT solenoid plays a crucial role in regulating airflow throughout the engine, affecting its entire range of revolutions per minute (RPM), such as the idle. Therefore, if the VVT solenoid goes bad, it can lead to a rough idle or stalling. This occurs when the camshaft timing becomes too retarded, causing the idle speed to drop excessively.

What are the symptoms of a bad VVT solenoid?

When the VVT solenoid goes bad, it produces different performance related symptoms, such as rough idle, poor engine performance, check engine light illumination, engine knock, or poor fuel economy.  

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