In the early to mid-1960's, American automotive giants Chrysler, Ford and General Motors ruled the streets and drag strips across the land. With every new car produced, the "Big Three" learned more about engine performance and how to squeeze every ounce of horsepower into their engines by manually adjusting valve lash and ignition timing. One of the biggest breakthroughs was the development of variable valve timing, a new program that utilized expanding electronic technology to apply variable electronic signals from the ignition system by way of a variable valve timing solenoid. This system is active in virtually all production vehicles sold throughout the United States today.
Each automotive manufacturer has their own unique VVT system, but most of them rely on a fully functional variable valve timing solenoid to control the flow of oil to the VVT system as it is engaged. This system typically activates when there is a significant load against the engine. Some examples of this include while a vehicle is carrying additional weight, traveling up hills or when acceleration is expedited through throttle control. When the VVT solenoid activates, oil is sent to lubricate the variable valve timing chain and gear assembly. If the VVT solenoid fails or is blocked, the lack of proper lubrication can cause the chain and gear to prematurely wear or break entirely.
There are multiple other problems that may occur when a VVT solenoid is wearing out or has broken that may extend to complete engine failure. In order to reduce the potential of these serious situations occurring, we've listed below a few of the warning signs to be aware of that might indicate a problem with the VVT solenoid exists. Here are a few symptoms of a worn out or broken VVT solenoid.
1. Check Engine Light comes on
Since today's modern cars are controlled by an Engine Control Unit, virtually all individual components are monitored by the ECU. When one part is beginning to fail, the ECU will store a specific code that will let a certified mechanic know that a problem exists. Once the code has been generated, it will signal the driver by illuminating a specific zone warning. The most common light to illuminate when a VVT solenoid is failing is the Check Engine Light.
Due to the fact that every automotive manufacturer has different codes they utilize, it's critical for a car owner to contact a local ASE Certified mechanic to inspect the car, download the code through the correct diagnostic tool and determine the precise source of the problem. In fact, there are literally dozens of individual codes for VVT solenoid issues for every automotive manufacturer. Once they have this initial information, they can begin to resolve the issue.
2. Engine oil is dirty
This is more of a cause as opposed to a symptom. The VVT solenoid works best when the engine oil is clean, free of debris, or has lost some of its lubricity or viscosity. When the engine oil becomes clogged with debris, dirt or other foreign particles, it tends to clog up the passageway from the solenoid to the VVT chain and gear. If your engine oil has not been changed out on schedule, it could damage the VVT solenoid, the VVT chain, and the gear drive.
To avoid this situation, make sure to have your engine oil changed out as recommended by the vehicle manufacture. Low oil levels can also cause problems with the VVT solenoid and other timing system components.
3. Rough engine idle
Typically the VVT system does not activate until the engine is at higher rpm's or is introduced to load bearing situations like climbing hills for example. However, if the VVT solenoid is malfunctioning, it is possible that it is introducing additional engine oil to the VVT gears. This can cause the engine to idle rough, specifically the engine RPM to fluctuate as the system is activated. If not checked quickly, it can cause additional engine components to wear prematurely. If your engine idle is rough, make sure to have a certified mechanic inspect this as soon as possible.
4. Decrease in fuel economy
The purpose of variable valve timing is to ensure that the valves open and close at the right time to maximize engine performance and reduce fuel consumption. 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.
If you recognize any of the above warning signs of a bad or failing variable valve timing solenoid, contact a local ASE certified mechanic so they can inspect your vehicle, replace the variable valve timing solenoid if needed, and keep your car or truck running strong.