4 Common Symptoms of cam phaser failure (Easy Solutions)

Owning a car means a lot of responsibility and maintenance to help your car function safely and properly. Therefore, you may need to know about the conditions of different parts of your car and what happens if these parts fail.

One of such integral parts of the car is its cam phasers. It is directly responsible for the performance of the VCT solenoids of your car.

So what happens when cam phasers go bad? A bad cam phaser will destroy the Variable Camshaft Timing (VCT) solenoids of your car. As a result, it will hurt the car timing.  Then, the engine might fail to start or come into an idle position. Eventually, your car engine will be damaged.

Since the cam phaser directly controls the car’s engine performance and is linked with your riding safety, you need to know when the cam phaser goes bad and needs replacement. It is also essential since reports show that a faulty or bad cam phaser is responsible for 5% to 10% of automobiles accidents in the USA.

What Is A Cam Phaser?

 Cam Phaser
sources: Youtube.com

Before we head into the functions of the cam phaser and what happens if cam phasers fail, let’s look at its definition first. It would help the car owner identify the parts easily as they might lack technical knowledge of their car.

Cam phasers have different names and terminology in the automobile industry. Some manufacturers refer to it as camshaft actuators. The main purpose of the camshaft phaser is to change the phase of the automobile’s camshaft while driving.

That’s why it gets the name cam phaser since it controls the phase or position of the camshaft. The position changing happens concerning the crankshaft of the car’s engine. As a result, you will see changes happening in the car’s variable timing or VCT.

In the modern-day internal combustion engine, the cam phaser will control the valve timing. You will see two kinds of cam phasers in the combustion engine. It includes:

  1. Exhaust
  2. Intake

Both parts of the engine may seem identical to look at, but they vary in functions. The cam phaser must have proper tolerance to withstand the temperature and abuses of the running engine in extreme situations. It is essential as the cam phaser will fail abruptly if it lacks the right tolerance level for the automobile.

What Happens When Cam Phasers Go Bad?

Now, it’s time to look at what a bad cam phaser might do to your car. Also, what happens to a failed cam phaser of your car?

When the cam phasers of your car go bad, it will hurt the Variable Camshaft Timing (VCT) solenoid of your car. On top of it, the ECU or Engine Control Unit of the car will also fail to control the phaser as it is linked directly with the camshaft functioning.

Since the cam phaser will no longer control the variable timing and positioning of the car’s camshaft, it would hamper the camshaft timing. Thus, you would experience loud noise coming out of the phaser, signifying that the cam phaser has stopped working.

But that’s not all. Eventually, it will fail to start the engine ignition. Thus, it will come to a standstill position where the engine might not even start or idle. It means the car engine will eventually fail, and you might need to replace it.

So, the entire process includes:

A bad cam phaser>Failure to control the VCT> ECU losing control over the phaser>Car engine might not idle or start> Failure of the car engine

Thus, you must ensure that the cam phaser is in good condition to avoid the failure of the camshaft phase changing and help the engine perform in proper condition. It is essential mainly for two reasons that include the following:

A bad cam phaser will lose control over the camshaft variable timing and might lead to accidents as the ECU also loses control over the VCT.

If not treated early, it will damage the engine. And replacing an automobile engine is no cheap and easy task.

Hence, if you don’t want to invest heavily in your car’s engine replacement and enjoy safe riding, you must maintain the cam phaser of the car with recommended guidelines from the car’s manufacturer.

Thankfully, the noises coming out of the car’s engine or crankshaft will easily tell you about the condition of the cam phase. When the cam phaser goes bad, your car or truck will emit the following loud noises:

You will hear a loud noise, much like tapping. It comes directly from the valve of the vehicle.

There’s even a louder knocking sound that comes out of the engine. It is constant and might feel irritating.

When you experience one or both kinds of noises from the car, it’s time you check the cam phaser to find what’s going wrong with it. Remember that a timely check and maintenance of the camshaft actuators will save huge money and possibly life on the roads.

The necessity of The Right Assembly of The Cam Phase:

Since the cam phase controls the engine performance and variable time-shifting of the camshaft, the parts must be assembled and mounted properly in your car. The assembling must be done under the proper supervision so that each component has the right tolerance level. 

If the assembly isn’t done appropriately and the cam phase lacks proper tolerance, the car won’t run smoothly and cause serious inconveniences on the roads.

With this importance of the cam phase assembly being said, you need to understand the testing parameters of the camshaft assembly. Once you know these complex parameters of assembling and testing the unit, you can quickly know its condition and avoid costly repairs.

  • The critical distance must be at the right setting.
  • The parts of each phaser must be attached and mounted correctly to its identical phaser.
  • There should be a debris screen. It showcases the debris present on the cam phaser and tells you when it needs cleaning.
  • The press force of the camshaft phase must be in proper and accurate settings and positions.
  • Finally, check the spring tension of the cam phase. It must be accurate.

4 most Common Symptoms of cam phaser failure

Symptoms of bad Cam Phaser
Sources: ford-trucks.com

We have already discussed the two possible noises of a bad cam phaser. But these noises aren’t the only signals of a bad cam phaser. In fact, car mechanics opine that there’re at least four symptoms that indicate a malfunctioning or bad cam phase.

When you know these suggestions, you can quickly check the cam phaser and take the necessary steps to fix it and avoid any accidents and inconvenience on the roads.

1. Clicking Sound

The most common and easily understandable sign of a malfunctioning cam phaser is the loud clicking sound. When the cam phaser fails, and the VCT isn’t working properly, the engine will generate a loud clicking sound, mostly when you start the engine.

There’s a car cylinder head in the cam sprocket of your car. When it starts wearing out, it fails to deliver the right amount of oil to the engine. So, the engine will have low oil pressure and lack proper power to start and run. As a result, it will growl, and you will experience the annoying clicking sound.

2. The Power Loss of the Engine

We have already been told that a bad cam phase will also result in less oil pressure for the car’s engine. So, you may experience a power loss and performance drop in the car’s engine.

Thus, look for the following signs:

  1. Misfiring of the engine
  2. Inaccurate acceleration
  3. Difficulty in starting the car

When you experience any or all of these signs in your car, it is highly likely that the cam phaser has stopped working or is in inaccurate condition. On top of it, the cam phaser failure will eventually result in losing the car’s mileage.

As the engine fails to get proper oil pressure, it fails to perform at its expected level. So, it will have less mileage compared to its standard.

3. Illumination of the CEL

CEL stands for Check Engine Light. When the cam phase fails, the CEL on your car’s console will start glowing to alert you of the worrying condition.

When the cam phaser stops working or fails, the ECU unit also starts working inappropriately. So, the ECU will gradually enter into a tottering or limping mode. It means the ECU will find it extremely difficult to function properly. As the ECU performance drops, it won’t deliver the proper power to the car’s engine, and it will have a reduced RPM.

So, the ECU will send an error code to the car’s console. You will, therefore, see the constant glowing of the CEL as a signal of improper cam phases.

4. Performance Drop

The engine will hardly reach 40RPM while driving the car due to the lack of proper oil pressure. Thus, you will see a drastic performance drop in your car’s engine. You will find it difficult to drive the car comfortably with a possible standstill of the engine anytime.

Also, as the engine finds it difficult to perform at its peak, it exerts too much pressure. Thus, the fuel economy of your vehicle will reduce dramatically.

Can I Fix A Bad Cam Phase?

When you see any or all of the symptoms mentioned above of a bad cam phase, you might need to replace it to avoid the complete failure of the engine. And changing the entire cam phase can be costly and time-consuming.

So, many car owners actually ask, “Can I fix the cam phase of my car?”

The good news is, yes, you can fix your cam phase even without replacing it entirely. But that depends on many conditions.

The main mechanical issues of a failed cam phase include:

  • Stuck timing chain failure
  • Stretching
  • Slack

And the electric issues may include:

  • Faulty solenoids
  • Failure of the camshaft timing sensor

The hydraulic issues are:

  • Low oil supply
  • Inappropriate oil viscosity

You have to diagnose the problem to know whether you can fix it or not. The best way of checking these issues is to get a scan tool. It will show you the correct error code so that you can find the problem precisely and start fixing it.

However, if the cam phaser fails entirely, you have to replace it ASAP to avoid costly engine repair or replacement.

Final Words

The failure of the cam phaser can be costlier, especially if you don’t repair it timely.  A bad cam phaser will hamper the functioning of the VCT and eventually damage the entire engine.

Thankfully, the engine’s clicking sound or performance drop quickly alerts you about the problematic cam phaser. When you find these symptoms, you should fix the problem ASAP and enjoy safe and comfy riding.

Who Worked on This?



I'm the guy responsible for ensuring that every blog post we publish is helpful for our reader.

Mahir Ahmed


I'm the guy responsible for ensuring honest, informative, accurate and helpful guide to the reader.

1 thought on “4 Common Symptoms of cam phaser failure (Easy Solutions)”

  1. My truck just has low power and shudders when giving it gas all at higher gears If i easy in to it runs normal

    I hear no loud clicking noise or anything of that nature

    I can go 80 mph no problem just got to ease into

    Is cam phasers or vct solenoid when hooked up to the scan tool. It says bad cam sensors but replaced then


Leave a Comment