Symptoms of Bad Cam Phasers – What they are and how to fix them

Cam phasers are essential components of variable valve timing (VVT). A technology added to most recent internal combustion engines to automatically help adjust the camshaft position under various working conditions. While the VVT works efficiently, it does experience some mechanical faults, most of which are linked to a bad cam phaser.

Since the cam phasers have much influence on the workability of the VVT, it’s crucial you’re able to identify the symptoms of bad cam phasers. And know exactly what to do before more damage occurs. But before I talk about these symptoms, let’s first look at what cam phasers are and how they work.

bad cam phaser sound

What are cam phasers, and how it works

To begin with, what is a cam phaser? Cam phasers are sprockets that help adjust the position of the camshafts depending on the crankshaft position when instructed by the vehicle’s computer. The camshaft itself is responsible for regulating the opening and closing of the valves depending on the position of the crankshaft and piston.

Most cam phasers operate hydraulically with the help of oil which enters through the VVT’s engine oil control solenoids.  These solenoids are electrical and are electronically controlled by the engine’s computer. Technically, while shifting of the camshaft is initiated by the engine’s computer, the camshaft’s shifts are done by the cam phasers with the help of the oil control solenoids.

Here is a simple explanation of how cam phasers work to adjust the position of camshafts. When your engine’s computer detects that shifting the camshafts to an extent will be favorable at particular conditions, it sends power to the oil control solenoids.  As power enters, the solenoid opens, letting out pressurized oil into their individual cam phasers.

The cam phasers properly working with the camshaft allow each valve to shift at the appropriate time. However, when the phasers are not in good shape, certain things start occurring in your car.

What are the symptoms of bad cam phasers?

The cam phasers are an essential component of VVT engines. When the VVT is faulty, you can quickly identify that the cam phasers are the issue by these symptoms. Thankfully, these symptoms are the same across all engines with the VVT.

Check engine light

Your engine’s computer initiates the working of the cam phasers. So if it senses the cam phasers are not cam phasing as they should, it prompts the engine check light to turn on. Depending on how the computer senses the issue, you will get a fault code.

It could be a generic code or other fault codes related to bad cam phasers symptoms such as rough running. However, don’t get it twisted; many other car problems also cause the check engine light to come on. So ensure you do a proper test with an OBDII scanner to ascertain if the cam phasers are the reasons the check engine light is on.

Clicking sound from the cams

When cam phasers start failing, they emit weird sounds totally different from any other car noise you’ve ever heard. But what does a bad cam phaser sound like?

Typically, a bad cam phaser sounds like a clicking mouse and is very loud. The clicking sound pops when cam phasers fail to stay in the appropriate position. Invariably causing the cams to float to an extent.

Decreased fuel efficiency

The cam phaser works with the engine’s computer, which prompts the cams to do their phasing. If, however, the cam phasers are faulty, they will fail to actuate the camshafts even when commanded by the computer to do so. Failure of the engine to actuate its camshafts leads to high combustion, invariably leading to increased fuel consumption.

Reduced engine performance

A bad cam phaser will not allow the engine to actuate its camshafts as it should. Invariably leading to low performance in certain working conditions.

While the engine may not totally shut out, you may notice a huge difference in how the car works when you step on the gas. This may include the engine acting slower or the car acting sluggish and weak.

Loss of engine power

When the engine fails to actuate the camshafts due to faulty cam phasers, performance often reduces. However, when the cam phasers are badly damaged, the car might enter limp mode (shutting down the engine) to prevent damage to the engine.

This should answer those asking, will bad cam phasers damage the engine? So if your engine suddenly loses power when driving, have your car towed and checked by a professional before driving again.

Rough running

When one or more cam phasers are faulty, performance is drastically reduced since the camshafts are not indexing correctly. This less-than-optimal performance invariably causes more noise and vibration, especially when idling.

The more the cam phasers deteriorate, the more this symptom increase resulting in knocking noise and regular engine stalling.

Rough running of vehicles may become prevalent in certain working conditions.

What causes cam phaser failure

While noting the symptoms of bad cam phasers is important, it’s also crucial you know why they fail. This will help you take preventive measures. Plus, you don’t have to wait until they fail before you act.

Improper lubrication

Cam phasers need engine oil for both operation and proper lubrication. If, however, they don’t get enough engine oil due to low oil pressure caused by degraded or contaminated engine oil, they can wear out over time. So ensure you change the engine oil at the recommended time so it doesn’t degrade or accumulate too much sludge.

Wear and tear inside the cam phasers.

 As cam phasers work, they are subjected to wear and tear due to continuous use. The phasers practically actuate multiple times every time you drive. So that’s enough to make it wear out. That’s why it’s essential to check the condition of the phasers from time to time, especially when they have recorded a high mileage.

Internal wear, such as damaged sprockets and gears inside the cam phasers, can also cause the cam phasers to get stuck. A stuck cam phaser will cause engine stalling and other engine problems. Here the stuck cam phaser or the entire valve train will need to be replaced to address the issue.


Like every other car component, cam phasers have their required lifespan. Once they have worked past this, they start failing. Here, replacing would suffice.

How do you fix cam phasers?

Cam phasers can’t be repaired, hence the need to install a new one. However, cam phasers are surrounded by other components, like the timing chain. Thus the installation is challenging—one reason most mechanics don’t recommend doing it yourself. So you may want to take the job to an expert as you may get stuck or cause more problems.

If, however, you want to go DIY, here is a step-by-step process to fix cam phasers. Note that each car brand, model, and engine type has a unique installation form; as such, a generic way might not be the best to follow.  However, here is how to install cam phasers for a Ford 5.4L engine.

  • Before starting the installation, disconnect the battery, remove the front tires if possible to make space for the repairs, and move any wires and connectors that might be in the way of getting to your cam phaser
  • Remove the engine front cover and crankshaft sensor, camshaft, and anything in the way of the cam phaser
  • Position the new camshaft phaser and sprocket and install two new phaser and bolts (ensure only hand tools are used to remove them to avoid damaging the camshaft or cam phaser and sprocket)
  • With the cam phaser locking tool, tighten the right and left-hand cam phaser sprocket bolts.
  • Then reinstall everything removed.

To, however, grasp a better insight into the process explained above, including how to check cam phasers, watch this video.

How much does it cost to have cam phasers replaced?

Cam phasers replacement costs between $800 and $2500, with parts lurking around $100-$400 and labor around $400-$2000. The discrepancies in the replacement cost lie in the fact that parts and labor costs may vary depending on your model.

Some cam phasers are more expensive than others. Likewise, labor in some models takes more time than others. So how long does it take to replace cam phasers? A complete installation of the cam phasers takes at least six hours, depending on the application.


What is a cam phaser lockout?

A cam phaser lockout is a modification done to a cam phaser to limit or eliminate the movement of the camshafts using the cam phaser lockout kit. Basically, the lockout kits do the work of the cam phasers, so there won’t be a need for one.

No cam phaser, no cam phaser problems, or other VVT components issues. So basically, a cam phaser lockout not only eliminates valve timing issues but also reduces clicking noise and vibration caused by a bad cam phaser. This invariably allows for better power and throttle response.

However, this might reduce vehicle performance in certain working conditions and also cause an increase in fuel consumption at higher RPM. The cam phaser lockout is achieved by inserting the lockout kit into the cam phaser gear without removing the front engine cover.

What does a cam phaser sensor do?

A cam phaser sensor monitors the position and movement of the cam phaser—the component responsible for adjusting the timing of the engine’s camshaft. Basically, the role of a cam phaser is to optimize valve timing based on engine load and speed. Invariably boosting performance, emissions, and fuel efficiency.

The sensor ensures the cam phaser operates correctly, enabling the engine to adjust its valve timing for optimal efficiency and power output.

Will a bad cam phaser throw a code?

Will bad cam phasers throw a code? Yes, bad cam phasers will throw a code. Which code it throws will depend on how the computer deduces the issue. It would throw a code whether the issue stems from the phasers or camshafts. To identify the exact problem, use an OBDII scanner for diagnosis.

Will a bad cam phaser cause a misfire?

Bad cam phasers can cause engine misfires. When cam phasers fail and prevent cam phasing, it won’t allow variable timing valves to adjust at the right time. Incorrect valve timings can cause rough idling and engine misfires.

What year Ford have cam phaser problems?

Ford cam phasers problems affected the 2017-2020 Fords built before November 2019, including the 2018-2020 expedition. However, while Ford vehicles are known for having cam phaser issues, they are prevalent in their 5.4L V8 and 3.5L engines.

Cam phasers issues in Ford are caused by improper lubrication of the cam phasers due to low oil pressure resulting from degraded or contaminated oil. Some models with this problem were due to their design. Hence, the Ford cam phaser recall made on these models in July 2022

What is the Ford Cam phaser rattle?

The Ford cam phaser rattle is a problem in Ford vehicles where the cam phaser fails due to wear inside the cam phaser and engine and starts making noise. The noise or rattle will increase with the cam phasers deteriorating.

Will a bad cam phaser cause a check engine light?

A faulty cam phaser will cause the check engine light. In fact, engine check lights turning on is a common gm 3.6 cam phaser failure symptom and many other vehicle models.

However, note that other car issues can also cause the illumination of the check engine light. To be sure the problem stems from the cam phasers, check for fault codes using an OBD II scanner.

Can you drive with a bad cam phaser?

You can drive with a bad cam phaser as your vehicle will still move. However, the question should be, should you drive with a bad cam phaser? No. Driving with bad cam phasers not only endangers you but other road users.

Moreover, even if you intend to drive with it, how long can you drive with bad cam phasers? If at all, a very short while. Because If it gets to a stage where your vehicle suddenly loses power, it might result in car accidents if it takes you unaware. Imagine stopping abruptly with a trailer almost near you.

Final Word

To sum it up, the most common symptoms of bad cam phasers are rough running, loss of engine power, low fuel economy, etc. It is important to identify them in time and fix them so they don’t affect other surrounding components and the engine. You can even help yourself by preventing its failure starting with engine oil needed for lubrication.

Ensure the oil is in good condition and at the right level. You can also check occasionally for wear and tear after recording certain mileage since the phasers turn regularly. Changing the camshaft when it has lived up its shelf life is another way of preventing cam phaser failure.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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