Why Is There Oil in My VVT Solenoid Connector? Causes & Solutions

Your vehicle comprises several components that help regulate the flow of oil throughout the engine. And one such component is the VVT solenoid. The variable timing valve solenoid typically helps control oil flow depending on the engine’s load and speed.

However, the VVT solenoid achieves this by working together with other components, one of which is the solenoid connector. And many drivers have reported seeing oil at the VVT solenoid connector. Thus, raises the obvious question: what causes oil in the VVT solenoid connector?

What causes oil in the VVT solenoid connector?

Oil in the VVT solenoid connector indicates the solenoid itself is faulty. First, how does the VVT solenoid work?  The VVT solenoid, also called an oil control valve, is part of the VVT solenoid system that helps regulate oil flow based on engine speed or load.

The VVT solenoid adjusts the camshaft position by retarding or advancing it using oil pressure, enabling smooth, effective engine operation. Generally, each camshaft is fitted with a VVT solenoid that adjusts the oil pressure supplied to the camshaft, depending on the engine’s load and speed.  Understand that the oil control valve is integrated into the VVT solenoid, so they operate synchronously.

Because it’s always in contact with oil, it will drip oil when it’s defective. And since the connector is attached to it, it makes sense that there will also be oil in the connector. So, if oil in the VVT solenoid connector means the VVT solenoid is faulty, what causes a defective or malfunctioning VVT solenoid?

Dirty or old oil

As oil flows through the engine, it picks up heat and other contaminants, making the oil thicken or become too dirty over time. Therefore, one routine maintenance item to keep up with is changing your oil to ensure you run on clean, less viscous oil. In fact, clean oil is essential for the easy flow of oil from the VVT to the VVT chain and gears.

If, however, you neglect this, dirty or over-thickened oil can cause a build-up of grime or sludge on the VVT itself or your solenoid filter screen (for cars with such a screen inside the valve).  The filter screen is found on the VVT solenoid, invariably delaying oil from reaching the VVT chains and gears.

However, one can avoid this by changing the oil at the recommended intervals, as specified by your vehicle manufacturer. If, however, you’re already in this situation, you can fix it by changing the oil and replacing the filter screen or the solenoid.

Aging bushings

VVT solenoids are mounted on rubber bushings. Over the years, these bushings can wear out because they are constantly soaked in oil. Failed rubber bushings can invariably cause the solenoid to move around and stop functioning as it should.

This is why it is crucial that you also check the condition of the rubber bushings when repairing or replacing a failed VVT solenoid.  And consider replacing these bushings if needed.

Symptoms of oil in the VVT solenoid connector

The VVT solenoid connector is attached to the top of the engine, where it operates with the VVT itself. However, it only served as a means of transferring power and should never have had oil on it. With oil on, it surely won’t work as intended.

But as already noted, an oily VVT solenoid connector means a defective VVT solenoid. So how do you know your VVT solenoid connector is faulty?

Illumination of the check engine light

Modern cars use an ECU, a computer that helps regulate the engine’s components. Therefore, if the ECU detects a fault in the VVT solenoid, it illuminates the check engine light on your dashboard.

However, while the illumination of the check engine light might be one of the symptoms of a failing VVT oil control valve, it could also mean something else. This is true because the ECU controls many other components and can trigger the CEL for different reasons.

So your best bet will be to diagnose with a scan tool. A failing component will always store a fault code, which will appear on the scanner during diagnosis. All you need to do is understand these fault codes; specific codes point to a failing component.

Poor fuel economy

One of the functions of the VVT solenoid is to ensure the intake and exhaust valves open and close at the right time. By so doing, you can ensure that minimum fuel is consumed. If, however, the VVT solenoid is faulty, the valves will open and close at the wrong time.

Thus, an increase in fuel consumption. So if you’re suddenly using more fuel than usual, the VVT solenoid may be worn. And a quick way to diagnose a bad solenoid is to look for oil in its connector.

Rough idling

Another essential function of the VVT solenoid is to supply more power when it detects your vehicle is working harder than usual or has reached a higher RPM. For example, when the VVT detects that your car’s load has increased or you’re going uphill, it automatically activates, providing more power for your vehicle.

If, however, the VVT solenoid is defective or the oil pressure is insufficient, your car will idle roughly because it can’t generate the power needed to perform such a task. While a faulty VVT can result in rough idling, several other components can also be responsible.

Poor engine performance

The VVT tends to save fuel and increase engine power depending on the camshaft position. However, if the VVT oil control valve is failing, engine performance may be reduced because the VVT solenoid may not be able to generate enough power for your engine.

When this happens, you will find it difficult to maintain high speeds, drive uphill, and even experience hard acceleration.

Ticking engine noise

A failing VVT solenoid restricts the VVT actuator from getting the oil pressure it needs. As such, you will hear a rattling or ticking noise from the engine.

So, for those asking,  can a VVT solenoid cause low oil pressure? Yes! The camshaft position is adjusted by oil flowing through the oil control valve. So if the VVT solenoid is faulty, oil flow will be reduced, ultimately reducing oil pressure.

How to test the VVT solenoid connector

While oil in the VVT solenoid connector points to a faulty solenoid, it’s good to make sure the connector is also in good shape. Because you might end up changing the solenoid only to be faced with a bad connector again, which means more time.

To avoid this, test the connector to see if it’s still working. If they are not, you could replace them when replacing the solenoids. So here is how to test VVT solenoid connectors. Connect a test light or a voltmeter to the connectors attached to the solenoid; it should supply power. If it does not provide power, your connectors may be failing.

How do you fix oil in the VVT solenoid connector?

We have established that the only reason you will have oil in the VVT solenoid connector is if the solenoid itself is malfunctioning. So your best bet in fixing an oily VVT solenoid connector is to fix the VVT solenoid. But you must make a proper diagnosis so you’re sure the VVT solenoid is truly bad. If so, here is how to fix the VVT solenoid.

Clean or replace, depending on the condition of your VVT solenoid. If it’s dirty, you can clean it, but if it’s leaky, you may need to replace it. So, for those asking, can you clean the VVT solenoid? Yes, you can. Just ensure you use the right cleaner, as some can damage the solenoid’s rubber parts.

So, what to use to clean the VVT solenoid? Your best bet will be a throttle body or mass airflow cleaner, as they can remove gunk or grime without damaging the rubber parts of the VVT solenoid. If, however, the VVT solenoid is broken or leaky, you should replace it with one suitable for your car.

Here, you need a new solenoid. So, how much is a VVT solenoid? A new VVT solenoid can cost between $203 and $224, depending on your car model. And if you’re replacing it yourself, you only need to buy the parts. If you go to a mechanic, replacement costs can climb to $317-$368, with labor costs estimated at around $114–$144.

While swapping in a new VVT solenoid, do well to clean the connectors, as they shouldn’t have oil on them; otherwise, they will lose connection. As stated above, be careful of what you use to clean it. Certain cleaners, such as brake or carb cleaners, should never be used on plastic electrical connectors, as they could damage the seals and plastic in the connector.

What to use to clean a VVT solenoid connector? A throttle body or mass air flow cleaner should suffice, as they can remove gunk or grime without melting plastic.  After the replacement and cleaning, do well to change your oil since old or dirty oil is the primary cause of a defective VVT solenoid.

Note that the codes thrown during diagnosis may not erase immediately after changing the solenoid. According to some vehicle manuals, it may take up to 3 driving cycles for the fault code to clear.

Final Words

Oil at the VVT solenoid connector indicates a defective VVT solenoid. So to fix the issue, you should clean or replace the VVT solenoid. However, since old or dirty oil is the main culprit of a failing VVT solenoid, you will need to change it when cleaning or replacing the solenoid. Otherwise, you will have the same issue again, which will invariably cause many car problems for you.