Symptoms of a Bad Variable Timing Solenoid And How to Replace It

Variable Valve Timing (VVT) solenoid is used in most modern cars to improve fuel economy and performance. VVT timing solenoid is responsible for altering valve lift timing in engines. This ensures that the right amount of oil is supplied to the engine at the right time, increasing fuel efficiency. 

Solenoid valves follow the electronic fundamentals of electromagnetism to control oil flow by drawing a miniscule amount of current from the battery. Passage of current and connection to the solenoid is interrupted when there is a bad VVT timing solenoid. This leads to problems while starting the car. 

Symptoms of Bad VVT Timing Solenoid

There are many symptoms of a bad timing belt. Some of these are:

1. RPM Fluctuations 

The first sign of a malfunctioning VVT timing solenoid is inappropriate idling in the engine. This is usually seen in the form of RPM fluctuations. Bad VVT timing results in the flow of additional oil to the engine. This causes the car to rev when idling. Inappropriate idling in an engine is usually the direct cause of rough handling. Ignoring the fluctuations in RPM can cause the engine to show signs of wear and tear early.

2. Check Engine Light

Electronic Control Unit (ECU) in modern cars allow for any unusual activity to be determined by the check engine light indication. ECU monitors are responsible for comparing and reporting all activity that takes place in the car, including the engine. The check engine light will turn on whenever any situation is found to be incompatible with predefined values. 

It is recommended that you take your car to a professional mechanic as soon possible to have it checked completely. It can be difficult to decode the engine light situation on your own. 

3. Fuel Economy

VVT solenoid is responsible for managing the open and shut timing of engine valves that allows oil to enter the engine. A bad VVT timing solenoid will not allow for optimal oil infusion and will reduce fuel efficiency. You would observe that the car is using more fuel than normal. 

You should look for definite drops in fuel average. Some people also smell “unburnt” fuel that indicates the VVT sensor is at fault. However, this is only true when the quality of engine oil remains high. Dirty or poor quality engine oil can directly affect the performance of the car. It may also lead to clogging in the Variable Valve Timing solenoid.

Replacing a Bad VVT Timing Solenoid

You should get your car’s VVT solenoid replaced as soon as possible when you detect and confirm that it is at fault. You can easily take care of the replacement on your own if you know your way around a car. If not, make sure you visit a reputable and certified auto mechanic. 

These steps need to be performed to replace a bad VVT timing solenoid correctly and quickly. 

1. Disconnect the Battery

You need to disconnect the car battery by loosening the terminals making sure there is no spillage of battery acid. This step needs to be performed with utmost care. Make sure you keep both the terminals away from each other at all times to prevent any possible short. Sometimes, there can be a small amount of charge stored in the capacitors. 

2. Open Engine Cover

The next step is to remove the engine’s plastic cover. This plastic body is different in every model. But, usually they are fastened with the help of nuts and bolts. Use the appropriate ratchet to remove all nuts and keep them in a safe place. 

3. Find the VVT Solenoid

Get the car manual to navigate your way inside the engine. Look carefully for the Variable Valve Timing solenoid, which is usually found around the valve corner. You can also search for it by comparing it with a picture or a new VVT solenoid (if you purchased one). Once found, clear the area of wires and other clutter. 

You should also look for mounts and bolts since the solenoid valves are usually tied using them. Mostly it is just a single bolt, but in some cases there can be two as well. Remove the bolts and make sure you don’t drop them accidently in the engine room. Keep them safe since they can be hard to replace. 

4. Remove the Old Solenoid

The first step to getting the old VVT solenoid out is to remove the connector fixed on it. Make sure that you do not disturb any connections to the connector. Press the tab on the side of the valve to release the lock. Use a pair of channel locks to remove the solenoid completely. You may have to grip the metal part and pull on it. If direct pulling doesn’t work, try using swirling motions to get the job done. 

Never throw out an old VVT timing solenoid without properly inspecting it. Sometimes, the problem is not with the solenoid but something else entirely. Have a proper look at it to make sure that it is faulty. You should also make sure that you have not left any side parts inside the engine room, like the O-ring. Use a clean and dry cloth to remove dust and debris before installing a new one. 

5. New Installation

Solenoids require adequate lubrication before they can be fixed. Make sure you lubricate it once you unbox it. Don’t forget to pay attention to the seals. Lubricate them with lithium grease. Place the solenoid in position and use the mounting screws to fasten it. Use an appropriate amount of torque to tighten the screws. 

Now, you need to put the connectors and jacks in place to the newly attached Variable Valve Timing solenoid. Make sure you apply dielectric grease to the connector’s face and seal to prevent corrosion. Check all the nuts and connectors again to make sure everything is as it should be. 

Put the engine cover back and fasten all screws. Reconnect the car’s battery and you are all set. 

Final Thoughts

A VVT timing solenoid is an integral part of your engine and plays an important role in the overall performance. Malfunctioning parts can result in faster wear and tear and even sometimes needing car body repairs.