Harry Gibson on January 31, 2023 No Comments
It’s challenging to keep track of all the moving parts in the engine because there are so many of them. But when something goes wrong, you need to identify which component it is. This makes a lot of people curious about the cam phaser, its symptoms, and potential replacement costs.
Do you have a suspicion that the cam phaser in your VVT engine is malfunctioning and are curious how to identify it? You’re at the right place. In this article, we delve deeper into each of these facets. Starting with the cam phaser’s function, followed by the symptoms that suggest that it is malfunctioning.
Finally, we’ll give an estimate of the replacement cost.
- Variable Valve Timing
- Cam Phasers And Their Function
- Symptoms Of Cam Phaser Failure
- Causes Of A Faulty Cam Phaser
- Cam Phaser Replacement And Cost
- Cam Phaser Lockout
- Final Conclusion
- FAQs
Variable Valve Timing
In order for a combustion engine to produce power, air must enter the cylinder chamber, and exhaust gases must leave. Intake and exhaust valves, respectively, are in charge of opening and closing these intake and exhaust passages.
Without variable valve timing, these intake and exhaust valves would function the same way regardless of the driving conditions or the engine’s RPM (revolutions per minute) speed. This isn’t ideal because the driver could like a different response from the engine as it revs.
For instance, the driver can want more power at higher RPMs while putting more emphasis on fuel efficiency at low RPMs and lighter engine loads. By altering how the intake and exhaust valves function at various engine speeds, variable valve timing permits these various behaviors.
As a result, it enhances engine performance while also enhancing fuel efficiency and emissions. Americans developed a valve with a variable opening time for an internal combustion engine in 1924. The requirement for variable valve timing was already recognized at that time.
However, the 2000 Spider from Alfa Romeo was the first production vehicle in the world to have a variable valve timing system installed which came out in 1980. The intake and exhaust valves are linked to a spinning camshaft that is located above the valves in order for them to open and close.
This is accomplished by using a variety of sensors, including airflow and camshaft position sensors. They supply data to the car ECU (engine control unit) of the vehicle. The ECU then employs a variety of processes to control the valve characteristics.
Variable valve timing is present in nearly all modern cars. Depending on how the system is set up, the technology can increase fuel efficiency, lower emissions, improve engine performance, or all of the above.
Cam Phasers
The heart of the VVT system is one or more camshaft actuator systems, often known as camshaft-phasers. The phasers adjust the camshaft positions to change the engine’s valve timing when the conditions are ideal.
Although camshaft phasers seem fantastic in principle, they frequently fail on many modern engines. In case you ever need to change the phasers, it’s helpful to have a fundamental understanding.
Inside the engine, there is a crankshaft and possibly one or more camshafts. A sequence of valves controlled by the camshafts open and close to let air (and fuel, in the case of port injection) into the engine and exhaust gases out.
In the meantime, the connecting rods and pistons are fastened to the crankshaft. The valves enable air to enter the engine’s cylinders and combine with gasoline when the vehicle is running. Small explosions are produced due to the mixture being ignited by the spark plugs. One of the engine’s pistons is forced downward by each explosion.
Your car’s crankshaft turns due to the movement of the pistons, producing the rotational force required to move the vehicle forward. The crankshaft and camshafts are connected by a timing chain (or timing belt). The shafts are to remain in sync because the valves must open and close at the proper points in the piston’s travel.
Working Of Cam Phasers
When the valves open and close in a conventional engine, the timing is fixed. However, a modern VVT system allows the camshaft(s) to be moved around, changing the valve timing. This capability can enhance engine performance, boost fuel efficiency, or both.
A typical VVT system is made up of several separate parts. In order to adjust the position of the camshaft and advance or retard valve timing, most vehicles use a phaser (aka the camshaft position actuator) that is hydraulically powered. The phaser is activated by applying pressure through an oil control valve/solenoid, also known as a VVT solenoid.
Based on information from numerous sensors, the PCM manages the solenoids that drive the VVT. Typically, each phaser has its own VVT solenoid. Some automobiles only have phasers on the intake or exhaust camshafts, whereas other automobiles have phasers on both.
Variable valve timing technology typically goes by a variety of names among automakers. For example, Ford refers to their system as Twin Independent Variable Camshaft Timing (Ti-VCT), whereas BMW refers to its technology as VANOS.
Honda refers to its technology as “VTEC,” (Variable Valve Timing and Lift Electronic Control) but Toyota uses “VVT-I” (Variable Valve Timing with Intelligence). You can learn more about the latter two in our guide on what is VTEC technology.
Symptoms Of Cam Phaser Failure
Cam phasers are a frequent problem with many modern autos. Phaser issues with Ford’s gas-powered full-size vehicles and SUVs are particularly well-known. As a result of a broken phaser, VVT solenoids will be harmed. The damaged VVT solenoids will render the ECU (engine control unit) incapable of controlling the phaser.
Lower engine performance and a check engine light are the most typical signs of a faulty cam phaser. Additionally, you might notice that the engine is noisier than usual, which needs prompt inspection and repair. The warning signals of a defective or failing cam phaser are listed in detail below:
1. Check Engine Light
When something goes amiss with the system, the car computer notifies you. With the aid of the powertrain control module (PCM), the camshaft positioning is constantly tracked by the camshaft sensor. The Check Engine Light will come on if the module receives unsatisfactory sensor readings.
The cam phaser is frequently the cause of this positioning issue, though it could also be due to some other issue. You should be able to pinpoint the issue more precisely by scanning the diagnostic trouble codes with a scanner.
Otherwise, this Check Engine Light might be prompted by a bad camshaft position sensor itself. So, it’s worth diagnosing more thoroughly, just to make sure. Therefore, you have to be wary of the symptoms of a bad camshaft position sensor.
Among those symptoms of a faulty camshaft position sensor includes OBD error codes such as:
For more insight, be sure to check out our detailed explainer on the P0014 error code on the Chevy Equinox. As well as, the location of the camshaft position sensor, and the camshaft position sensor bank 1. On top of that, we also discussed the cost of a replacement camshaft.
2. Limited Engine Performance
By modifying the oil pressure so that the cam phaser can modify the valve timing, the PCM optimizes the intake valve through the cam phaser. But when the phaser malfunctions, the PCM is unable to regulate the timing of the intake valve. For the engine to function as intended, the valve timing needs to be optimized.
Timing will either be advanced or retarded if the phaser isn’t functioning properly. The engine will have performance concerns as a result of either of these situations. You may experience difficulty accelerating, a harsh idle, or difficulty obtaining all of the power it often produces.
Also, if the PCM is unable to maintain control over the valve timing, the ECU side of the PCM will start engine protection operations. In order to safeguard the engine, the ECU will lock the VVT in this mode. Sadly, this setting restricts the engine’s maximum RPM and horsepower to a lower overall level.
3. Cam Phaser Rattle
When the engine is running at its base idle, the phaser should lock into place. However, it might not be able to lock in place if the phaser has failed. The end outcome is a knocking or rattling sound. It should be audible coming from the motor’s top. When the engine is idling or after it has warmed up, it will be more evident.
Causes Of A Faulty Cam Phaser
Without taking into account high mileage and wear over time, issues with engine oil are the main factor contributing to cam phaser failure. Motor oil fulfills the lubricating needs of cam phasers. Low oil pressure will result in insufficient lubrication for the cam actuator, which will hasten its deterioration.
The cam phasers and the entire engine will be damaged if you don’t change the oil properly (and learn how to change oil in car) and allow it to separate, degrade, and accumulate sludge. The oil change intervals should be respected by all owners since it is the most crucial auto maintenance you can do. The following are the specific causes of a faulty cam phaser.
1. Low Oil Pressure
To power each cam phaser, the proper quantity of oil pressure is required. The cam actuator will malfunction if there is insufficient pressure. Your car’s oil quality or a malfunctioning oil pump may be the cause of low oil pressure.
Due to the phasers’ metal construction and need for maintenance, low oil pressure can also cause internal wear. To figure out more, do refer to our write-up on what does the low oil pressure light mean. Additionally, we discussed other issues, such as what is considered to be low oil pressure.
On top of that, we looked into other problems like experiencing low oil pressure at idle. Or, if you’re noticing a ‘oil pressure low stop engine’ warning message on your dash.
2. Wrong Oil Type
Cam phaser issues can also arise from using the incorrect oil. Oil with the specified viscosity is necessary to generate the required pressure to move the cam phaser to the appropriate position as needed. The wrong oil won’t be able to generate the pressure required to advance the cam phaser to the proper position.
The response time of the cam phaser will be impacted by the oil’s viscosity, which can cause issues. To maintain optimum friction and lubrication, the oil viscosity must be appropriate for the engine.
Improper viscosity might cause a lot of wear because the engine is operating at excessive temperatures all the time. You can ensure proper pressure by using the right oil. For more context, you can check out our many motor oil type articles as of late, including:
- 2016 Nissan Rogue oil type
- 2009 Toyota Camry oil type
- 2017 Honda Civic oil type
- 2013 Chevy Malibu oil type
3. Dirty Oil
As the oil ages, sludge, dirt, and other contaminants pollute it. For example, when there are metal shavings in the oil. These factors collectively result in a decreased oil flow, which has an impact on the health of the cam phasers. Because of this, you should always change the oil at the recommended intervals.
Oil fluctuates in thickness when it gets dirty. The position of the cam phaser can only be adjusted much more slowly in thicker, unclean oil when the engine requires it. In contrast, synthetic oil doesn’t require frequent replacement as conventional oil. To guarantee the oil stays fresh, remember to change the oil filter at the same time.
If you need further references, our guide on do you have to change the oil filter every time might prove insightful. Otherwise, it’s not a good idea to test what happens if you don’t change your engine oil, or how many miles can you go over an oil change.
4. Faulty Gear Sprocket
The gears and sprockets are also kept lubricated by motor oil. The cam phaser will experience issues if there is too much friction, which will cause these expensive components to fail prematurely.
Friction modifiers can be added for less wear if you are concerned about proper lubrication. However, today’s leading oil producers offer everything required to keep the engine running efficiently.
5. Faulty ECU
The ECU controls the cam phasers and monitors their functioning. Hence, the phasers could malfunction if the computer can’t function properly. You can rapidly identify these ECU issues with a code scanner. You can make sure the phasers keep operating as they should by fixing the faulty ECU and being wary of the bad ECU symptoms.
Cam Phaser Replacement
A replacement is the only solution for a broken cam phaser. But first, it’s critical to figure out what went wrong with the cam phaser in the first place. If the underlying issue is not resolved, the replacement cam phaser won’t survive very long.
Unfortunately, the timing belt/chain needs to be maneuvered around in order to replace the cam phasers. Hence this repair process isn’t recommended for a DIYer.
As you’re much more likely to become bogged down in the procedure or create new issues than to solve the initial problem, we strongly advise leaving this process to a professional. 
Cam Phaser Replacement Cost
The typical cost for replacing a cam phaser is between $800 and $2,500. Your car’s make, model, and the mechanic you choose will all affect the final cost. A significant chunk of this expense will be the mechanic labor rate because replacing a cam actuator is a challenging task.
The replacement of a cam actuator is not an easy task. To change the cam phaser, a lot of effort must be done in order to reach it; this process could take up to four hours. By replacing it yourself, you can save some money if you have the requisite experience.
However, the cost of DIY replacement kits continues to range from $200 to over $1,000.
Driving With Bad Cam Phasers
You don’t want to keep driving your car if you know the cam phasers are faulty. If you keep going, you run the danger of damaging the car even if it keeps running without too many interruptions. The defective phaser could further harm the motor, solenoids, ECU, exhaust, or intake valves.
If you put off the repair you could end up with a bigger price later on. Suddenly loss of power while driving is another possibility. This issue puts you at risk for an accident and puts other drivers on the road in danger. When the vehicle can be fixed, there’s no need to expose others to dangerous situations.
In reality, you can continue to drive your car with broken cam phasers until the engine gives out. However, remember that the more you drive a car with bad cam actuators, the more harm it will do. The cost of repair will increase with the extent of the damage.
Cam Phaser Lockout
A piece of aluminum that is intended to fit in one of the spaces between the vanes of a cam phaser is called a cam phaser lockout. This is how the cam phaser lockout restricts the movement of a cam phaser’s vanes to stop a cam phaser rattling. A cam phaser lockout enables you to maintain stability and disable default VVT operation.
In other words, cam phaser lockouts are really a band-aid for a worn-out cam phaser. It could have been damaged because of low oil pressure, a broken timing chain, a blown tensioner seal, or a bad VVT solenoid (as noted with a P0012 or P0013 OBD error code, if you have a bad VCT solenoid).
A cam phaser lockout kit is an inexpensive and speedy solution to the cam phaser rattle problem. A complete cam phaser kit (VCT solenoid, tensioners, timing chain, and cam phaser) costs more than $2,000.
On the other side, you can make your engine run smoother and quieter by locking out the cam phaser with a cam phaser lockout kit that costs less than $100. The drawback of a cam phaser lockout is that it does not provide a long-term solution.
You can use it as a low-cost remedy if your engine is old and you do not put too much strain on it. However, the timing belt, tensioner seal, and cam phaser should all be replaced if your engine has only a few thousand miles on it and has serious cam phaser issues.
Another drawback of cam phaser lockout is the high price of the engine tuner that is necessary while installing the kit. About $600 will buy you a tuner. As the engine loses some power due to the lockout, it needs to be carefully tuned to enhance engine performance.
Cam Phaser Lockout Kit
A cam phaser lockout kit is designed to stop the clacking of the cam phaser. It does this by restricting the cam phaser’s movement and positioning it in the fully advanced position. The cam phaser vanes are fitted with a tiny metal block.
The vanes can be prevented from moving in either direction by putting an aluminum block between them. Since the cam phaser’s vanes won’t clack as a result of timing chain or oil pressure issues in the engine, locking out the cam phaser will stop it from rattling.
The lockout will lock the internal mechanics of the cam phaser. This converts it into a fixed timing gear without any moving components or internal mechanisms to create noise or break down.
The cam phaser lockout kit also includes a tuner. This enables you to modify or reprogram the engine control module according to your cam phaser settings and use lockouts to enhance engine performance. A trouble code may be generated and the check engine light may illuminate when there is an issue with the cam phaser.
Hence, after installing the cam phaser lockout kit, the main goal of the engine chips tuner will be to turn off the check engine light. The engine control module will not be able to alter the cam phasing thanks to the tuner’s reprogramming of the PCM (powertrain control module).
A fault code that would normally be generated as a result of the cam not retarding or advancing properly can be blocked by custom tuning of the ECM. To summarise, adjusting an ECU (Engine Control Unit) assures that it can no longer tamper with the cam timing.
Cam Phaser: Conclusion
There are several ways that cam phaser issues can manifest themselves, including rattling and knocking noises, rough running and stalling of the engine, poor performance, and poor gas response. It’s crucial to address the problem right away.
More serious problems, such as incorrect camshaft timing, can result from a faulty phaser. Ignoring the symptoms could cause major engine damage, which would require expensive repairs. You should check the ECU for error codes and determine the cause whenever any of these symptoms manifest.
Before deciding how to resolve the problem, you should get the car diagnosed by a mechanic. Cam phaser replacement costs are high. For a professional to complete the task, you need to budget between $800 and $2500. Naturally, there are a number of variables that will affect the final price, including the vehicle’s year, make, and model.
FAQs On Cam Phaser
What Is A Cam Phaser
A cam phaser is a sprocket that uses a computer-controlled servo to fine-tune the position of an engine’s camshaft in relation to its crankshaft. The timing of an engine’s intake and exhaust valves, which in turn determine how aggressively an engine performs, is controlled by the camshaft.
How Long Can You Drive With Bad Cam Phasers
There is no fixed time. You can keep driving the car till it breaks down. However, the longer a car is driven with defective cam phasers, the more it damages the engine. It can even result in needing a VVT-solenoid or ECU replacement or expensive engine repairs. It makes sense to have issues examined before they cost you a lot of money.
What Are The Symptoms Of A Bad Cam Phaser
Weaker engine performance and a check engine light on your dashboard are the most typical signs of a faulty cam phaser. Additionally, you might notice that the engine is noisier than usual, which needs prompt inspection and repair.
What Does A Bad Camshaft Sound Like
Frequent popping and backfiring are signs of a faulty camshaft. At both low and high speeds, you could also encounter cylinder misfires. You can also hear tapping and ticking noises coming from the upper side of the engine if your camshaft lobes are worn.
How To Quiet Cam Phaser Noise
With an oil treatment or a cam phaser lockout kit, you can lessen the noise produced by the cam phaser. These are cheap short-term treatments that might give you some time. But ultimately you must choose the long-term fix and replace the phasers.
How Do Cam Phasers Work
A crankshaft and perhaps multiple camshafts are found inside an engine. In order to let air into the engine and exhaust gases out, a number of valves are opened and closed by the camshafts. By adjusting the camshaft’s location or phase in reference to the crankshaft, cam phasers change the timing of the valves.
What Is A Cam Phaser Rattle
The problem is caused by a pin in the cam phaser that is intended to lock into position once the engine is turned off. However, this pin won’t always lock into place. This means that the phasers spin freely before sufficient oil pressure has been produced, which results in a rattling.
