Heat Transfer.

In internal combustion engines, variable valve timing (VVT) is the process of altering the timing of a valve lift event, and is often used to improve performance, fuel economy or emissions. Two-stroke engines use a power valve system to get similar results to VVT.

EGR (Exhaust gas recirculation) is a commonly adopted technique to reduce emission and improve fuel efficiency. However, it is VVT that really exploit the full potential of EGR. In theory, maximum overlap is needed between intake valves and exhaust valves’ opening whenever the engine is running at high speed.

• (i) Duration of combustion of the charge. This increases the heat loss.
• (ii) Temperature of combustion.
• (Hi) Speed of the engine.
• (iv) Shape of the combustion space.
• (v) Size of the cylinder.
• (vi) Ignition timing in S.I. engines and fuel injection timing in C.I. engines.

Chevrolet’s VVT system uses electro-hydraulic actuators between the drive sprocket and camshaft to twist the cam relative to the crankshaft position. Adjusting the cam phasing in this manner allows the valves that are actuated by that camshaft to be opened and closed earlier or later.

There are many benefits to using VVT and virtually no drawbacks. One benefit is an increase in maximum engine speed (and therefore more peak power) – as much as a 25% increase. The exhaust gas recirculation reduces the amount of fuel needed to run the engine and therefore boosts the all-important MPG number.

The average cost for variable valve timing control solenoid replacement is between $375 and $449. Labor costs are estimated between $178 and $224 while parts are priced between $198 and $225.

Can You Drive with a Bad VVT Solenoid? Even though you may technically be able to continue driving with a bad VVT solenoid, the issue can cause damage to additional parts, such as the VVT actuator. So, you should address the issue as soon as possible.

When the VVT solenoid is malfunctioning, the entire system can be compromised, which may result in intake and exhaust valves opening and closing at the wrong time. This typically causes the fuel economy to drastically reduce.

5 Symptoms of a Bad Variable Valve Timing (VVT) Solenoid

• Check Engine Light.
• Rough Idling.
• Rough Acceleration.
• Increased Fuel Consumption.
• Low engine performance.

Part 1 of 1: Replacing the variable valve timing solenoid

1. Materials Needed.
2. Step 1: Raise and secure hood.
3. Step 2: Disconnect the battery.
4. Step 3: Locating the variable valve timing solenoid.
5. Step 4: Clear the area.
6. Step 5: Locate the mounting bolts.
7. Step 6: Remove the mounting bolts.
8. Step 7: Disconnect solenoid.

The variable valve timing solenoid is a component of the variable valve timing system that manages the oil flow depending on the engine speed and load. A VVT solenoid in good working condition improves performance and fuel efficiency. Machined to precision tolerances preventing leakage, wear and seizing.

A faulty VVT switch will also cause the engine to misfire or appear to stumble when your vehicle is loaded with extra weight, climbing hills, or when you apply quick pressure to the throttle for instant acceleration. This is caused commonly by an electrical issue with the switch and not always the switch itself.

Hugh Hunkeler, Three decades of automotive engineering. How long can you drive with a bad solenoid? It depends on the solenoid. If it’s the one that opens your trunk with the button on the key fob, you can drive indefinitely.

If your VCT solenoid is going bad or has gone bad on you, it’ll usually result in your car’s check engine light coming on. This is one of the reasons why you shouldn’t ever ignore the check engine light, as it could indicate a serious issue with a part as important as your VCT solenoid.

When a cam phaser goes bad they will almost always do several things. Key word being “almost”. What will happen in this situation is the ECU will do everything possible to protect the engine. It will go into safe (or limp) mode, which will in most cases, and stop the engine from going over a certain RPM.

Typically, worn phasers create a loud and rough idle. Often, a knocking noise is heard. In some instances, the noise is not due to wear in the phasers but rather low oil pressure due to cam bearing wear in the cylinder heads. If that is the case, the heads may need to be replaced or machined.

VVT (variable valve timing) is a general term for the system that keeps timing of the valves, and is typically designed to work with the camshaft. A VCT (variable cam timing) can be considered a form of VVT system. Manufactures changes the names to make them sound like “manufacture specific” designs.

Twin Independent Variable Camshaft Timing

VVT = Variable Valve Timing. A general term for any system that can make the valves open and close earlier or later in the piston cycle, whether through cam phasing or some other method. In other words, VVT is a blanket term; VCT is a type of VVT.

For a VCT solenoid replacement, you will pay between $80 and $410. The labor on that replacement should be between $30 and $155, while parts should be between $50 and $255.

Transmission Solenoid Replacement Cost – Parts & Labor

VTC (Valve Timing Control system) VTC continuously varies valve timing with engine speed, temperature, and load of engine. Engine Control Unit(ECU) computes the required information of engine speed, temperature, and accelerator opening, and sends the control signal to Solenoid Valve.

The Oil Control Valve (OCV) is a a critical part used in every engine that is fitted with variable valve technology (VVT). Controlled by the ECU, the OCV receives electrical signals, instructing it to adjust the oil flow as required, in accordance to current driving conditions.

Our CNC Billet Cam Phaser Lockouts will completely lock the cam timing in the fully advanced position and will eliminate movement and noise associated with failing cam phasers. Cam phaser knock is a common problem in the 5.4 3V Ford Trucks especially in higher mileage or fleet applications.

Replacement of the phasers alone is not the correct repair, all of the cam followers are to be replaced as well. If the phasers were replaced improperly then it could possibly cause engine damage, but it also would not run right once repair was completed.

However, if you ask specifically for a phaser replacement, you will pay somewhere from $550 to $850.