Symptoms of a Bad Oil Control Valve (and How it Works)

Last Updated on November 20, 2019

An oil control valve is commonly used on engine with variable valve timing (VVT) system. This system is to control the engine performance using the method of retard and advance camshaft angle.

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The benefits of a VVT system include: Fuel consumption efficiency, reduced gas emission, and increased engine performance. For more information about the oil control valve, please read the full article below:

What an Oil Control Valve Does

The oil control valve is controlled by the engine control module, or ECM. The oil control valve is basically what controls the flow of oil into the camshaft of the engine. This allows the internal moving parts of the engine to sustain their functionality.

If the camshaft cannot be lubricated at the right times by the oil, then the engine won’t be able to perform its job properly. So, what the oil control valve does is it opens and closes the camshaft at the appropriate times to let in oil when it is needed and prevent oil from entering when it is not needed.

The ECM will control the valve and let it know what appropriate action it must take based on the engine’s performance demands.

Common Symptoms of a Bad Oil Control Valve

If you have oil control valve problems, then there are certain symptoms you can look out for. Some of them include slow acceleration, poor brake performance, and a strange burning smell in the car.

Before it gets this bad, the computer in your vehicle should give you some warnings first on the dashboard. The most obvious warning will be when the “Check Engine” light is on. You may not know exactly why it’s on unless you experience those other symptoms mentioned before.

And also the fuel economy is what will be affected the most. Remember if the oil control valve doesn’t manage the flow of oil properly then it will cause the engine to overperform and use up more fuel. This means you’ll be spending more money on gas while causing your exhaust valves to open and close at the wrong time.

Sooner or later, the internal components of your engine will get damaged as a result. That is why it is best to take care of these problems as soon as you notice them happening. It is a lot cheaper to change your oil or replace the oil control valve then it is to replace your engine.

Common Causes of a Faulty Oil Control Valve

Believe it or not, there are lots of people who forget to change their oil on time. The reason you need to change your oil every 3-6 months, or every 5,000 miles, or whatever the manufacturer recommends is because debris and dirt build up in the oil after a while.

If the oil does not get changed then it will create a blockage which will prevent the oil from flowing into the camshaft and will cause the oil control valve malfunction. So always remember to change your oil and keep it as clean as you can.



  1. I have a 06 Mazda 6 v6 and my front oil control valve moves slightly left and right. But my oil control valve on the back valve cover does not move at all. What does that mean? I know it’s most likely bad but whyis it moving. Is my camshaft bad or what??

  2. It means ur car engine is gonna suffer, this thing damaged 2 engines on my car in 2 weeks. Trust me I have just ordered 2 new solenoids to put on 3rd engine. Don’t joke with those things replace them

    • Yes, the device usually has a filter with a screen that can collect debris and create a blockage.

      It’s also a common part to fail, enough so that Ford/Mazda have done recalls on in the past, but rarely when anyone needs it and rarely would they warranty because they’d find a reason not to. Be it timing vs mileage, sludge/maintenance , mods, or just plain “because” they can.
      Expect timing problems in the newer vehicles to be associated with this oil control valve, see VVT recalls at NHTSA or car problems. Com for reference.

      Lack of oil at the right time will cause rapide excessive wear to your cylinder head camshaft and it’s journal bearings. In my L3 VDT Engine, it grooved the camshafts so badly it welded the aluminum oil hole closed. The heat from friction and unmistakable putrid stank of burning melting aluminum and oil is one I’ll never forget. It warped the head, causing the timing to go off or vice versa. If you have kR knock retard values u can measure with a VCI scan tool or elm327, anything above a 3.0kR is certain Doom.

      How does this happen? See Kobe steel Manufacturing scandel. See the international monopolies bearing manufacturers have, and ever growing demand for off the shelf seemingly effecient cars with no engineering for longevity. Ford/Mazda are not the only Manufacturers associated with these problems, they ALL have them, some more some less


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