Bad Variable Valve Timing (VVT) Solenoid Symptoms & Replacement Cost

Variable Valve Timing (VVT) solenoids are one of the greatest innovations in the automotive industry.

Almost all modern cars use VVT technology to improve their performance and fuel economy. The VVT solenoid helps engines change their valve lift control, which ensures that the correct amount of oil is supplied to the engine, resulting in reduced fuel consumption.

Electronic principles of electromagnetism in the form of a solenoid valve are used to control this oil flow. The solenoid valve draws a small amount of current from the car battery and activates it.

When the ignition is switched on, the connection to the solenoid valve is made and a metal bracket is pulled down, overcoming the spring force and pushing the bracket away. This pressure closes the contact between the terminals and connects the battery to the starter so that a large current flows through the contact to the starter and the engine starts.

If the solenoid coil is defective, the passage of current is interrupted, which leads to a starting problem. This may be due to burns or corroded contacts.

If the VVT solenoid malfunctions, improper lubrication can cause damage to the gearbox and timing chain.

Bad Variable Valve Timing (VVT) Solenoid Symptoms

There could be a variety of symptoms and effects of the faulty timing belt. They are all as follows:

1. Indicating Check Engine Light

With the help of the Electronic Controlled Unit (ECU) with which modern new vehicles are equipped, you can learn about any unusual activity going on in your vehicle via the check engine light. Your ECU monitors compare and report any activity going on in your car, and in case one of the current situations is not compatible with the predefined values, the check engine light comes on.

In this case, it is advisable to consult a highly professional mechanic and have your car checked, as only he can check and decode the check engine light via his manual.

2. Rough Idling

The flow of additional oil to the VVT gearboxes is one of the possible results when the VVT solenoid coil fails. This leads to a rough idling of the engine. The engine speed fluctuates when the VVT gearbox is working. If the speed fluctuations are ignored, this can lead to premature wear of the engine.

3. Dirty or Bad Engine Oil

The performance of VVT magnets depends strongly on the quality of your engine oil. With clean engine oil they tend to work perfectly. Engine oil with many impurities lowers its viscosity, which leads to clogging of the VVT solenoid, which ultimately affects the chain and gearbox.

4. Reduction in Fuel Economy

VVT solenoid manages the opening and closing times of the valves to ensure that efficient fuel consumption is maintained. Any malfunction of the VVT solenoid is therefore certain to result in efficient fuel consumption. So if you notice a significant drop in your average fuel consumption and smell of unburned fuel, it is very likely that your variable valve timing sensor is defective.

Replacement of the Variable Valve Timing (VVT) Solenoid

Once it has been determined and confirmed that the VVT solenoid of your car is defective, it is recommended that you have it replaced by a professional mechanic or replace it yourself if you know how to do it. The following steps must be carried out for the replacement.

Disconnect the battery

First, carefully disconnect the car battery from your car by gently loosening both poles, being careful to avoid spillage of any battery acid. Keep both poles away from each other to avoid a possible short circuit due to a charge stored in the capacitors.

Open the Engine Cover

Your engines are covered with a plastic body (different for each model) under which all other engine parts are hidden. So first remove your engine cover by loosening the nuts on the cover, and store it securely to one side.

Find the VVT Solenoid

When the cover is removed, now carefully search for your VVT solenoid. It is normally located around the valve cover. If you don’t know and you have a new VVT solenoid, try to compare the two and find a similar part mounted somewhere nearby, as it will make your search easier. When you have found it, make sure that this area is cleaned of wires and other parts.

Look for Mounts and Bolts

Normally solenoid valves are fixed with a single bolt, but in some cases there are also two bolts. Remove these bolts carefully and keep them safe, taking care not to drop them into the engine.

Take the Old Solenoid off

First, carefully remove the connector attached to the VVT solenoid by pressing the tab to release the locking device, ensuring that no connections to the connector are disturbed. Now remove the solenoid using a pair of channel locks. Grasp the metal part and pull on it. Try to swirl and pull it, as this may make your pulling more effective.

Inspect Faulty Solenoid

When you have removed the solenoid coil, take a good look at it. Make sure that the entire solenoid coil has been removed and that none of its side parts such as the O-ring etc. are still there. Also, make sure that you remove any dust and debris if it is found there.

Install New Solenoid

After you unpack your new solenoid coil, lubricate it before you start the repair. Also lubricate the seals with lithium grease.

Secure it tightly

Now bring back the mounting screws you removed from the old solenoid, and fasten them firmly. Make sure that they are tightened well to precise torque.

Connect Everything up

Now plug all sockets and plugs onto this newly attached VVT solenoid. Applying dielectric grease to the seal and connector surfaces is recommended as it helps prevent corrosion.

Packing Back

When all the above steps are completed, replace the engine cover and reconnect the battery. You are now ready to start.

VVT Solenoid Replacement Cost

The average replacement cost of the VVT magnet is about $300. You can expect labor costs of $50-300 depending on the car model, and the part itself costs between $50-300.

With VVT solenoids, there is a large price variance depending on the car you have. For some car models you have to take half the engine apart, for others, it can be replaced within 5 minutes. You will find detailed information in your repair manual.

Conclusion

VVT solenoids play an important role in the overall performance of your car. A malfunction of the VVT magnet means a disturbance of the engine activity, which can possibly lead to engine wear.

If you have questions about the VVT solenoid, please leave a comment below!

Magnus Sellén

Hello I'm Magnus, the owner and the writer of this website. I have been working with cars since I was 16 and I'm specialized with in-depth Automotive diagnostics. Also been driving drifting for the last 6 years. I'm here to give you answers to all your automotive questions and I hope that you enjoy our content.