Question 1

What is variable valve timing (VVT)?

Accepted Answer

VVT is a system designed to adjust the timing of an engines valves to optimize performance and lower emissions throughout the engines entire operating range

Question 2

How does VVT work?

Accepted Answer

There are several systems and methods used to achieve VVT. Modern VVT systems are computer controlled and utilize electrical solenoids to control valve timing change. When the solenoids are energized, they act upon the components used in the system for making the mechanical timing adjustment. This is commonly done hydraulically with the use of pressurized engine oil, although some systems vary in design.

Question 3

What vehicles have VVT systems?

Accepted Answer

VVT systems have become extremely common, almost all vehicles today come equipped with some form of variable valve timing system.

Question 4

Do I need to maintain my VVT system?

Accepted Answer

While most VVT system components are maintenance free. The VVT system is greatly affected by engine oil condition and viscosity. For your VVT system to operate properly, you must service your engine oil regularly following the manufactures recommended intervals.

Question 5

What happens when a VVT system Fails?

Accepted Answer

The level of concern regarding the failure of a VVT system depends on the type and severity of the failure. While a failed VVT solenoid might cause poor engine performance and the check engine light to illuminate, it can also fail due to low engine oil or low engine oil pressure, which may lead to severe engine damage.

Question 6

What are common VVT failures?

Accepted Answer

Engine oil issues, such as low level, poor condition, or incorrect viscosity
VVT solenoid failure
Circuit/Wiring problems

Question 7

What are VVT ssystem components?

Accepted Answer

VVT solenoid
Camshaft actuator/phaser
Oil control valve/spool valve
VVT oil pressure switch
Engine oil passages
Camshaft and Crankshaft position sensors
Engine control module