22 May 2024
Learn about the signs of a failing camshaft and how to replace it. Loss of power, engine misfires, decreased fuel efficiency, strange noises, and more.

So, you’ve noticed some odd noises coming from your engine, and you’re starting to suspect that something might be wrong with your camshaft. Don’t worry, you’re not alone! Many car owners have experienced issues with their camshaft, and knowing the signs of a failing one can save you from further damage down the road. In this article, we’ll explore the common symptoms of a failing camshaft and guide you through the process of replacing it, so you can get your engine purring smoothly once again.

Signs of a Failing Camshaft

Loss of Power

One of the key signs indicating a failing camshaft is a noticeable loss of power in your vehicle’s engine. If you find that your car struggles to accelerate or feels significantly weaker than usual, it could be a sign that the camshaft is not operating properly. The camshaft plays a crucial role in controlling the timing and duration of the engine’s valves, which directly affects the power output. Any issues with the camshaft can result in a significant decrease in overall engine performance.

Engine Misfires

Another common symptom of a failing camshaft is frequent engine misfires. A misfire occurs when one or more cylinders in the engine fail to ignite properly. This can be caused by the camshaft not opening the valves at the correct time, resulting in a disruption of the combustion process. If you notice your engine stumbling, hesitating, or experiencing intermittent power loss, it is likely that the camshaft needs attention.

Decreased Fuel Efficiency

A failing camshaft can also contribute to decreased fuel efficiency in your vehicle. When the camshaft is not functioning optimally, it can affect the timing of the valves, leading to poor air-fuel combustion. This inefficiency can result in fuel being wasted, causing your vehicle to consume more fuel to achieve the same level of performance. If you find that you are making more frequent trips to the gas station without any significant change in your driving habits, it might be worth considering a potential issue with the camshaft.

Excessive Exhaust Smoke

Excessive smoke coming from your exhaust pipe is another sign that your camshaft may be failing. A faulty camshaft can disrupt the combustion process, leading to incomplete burning of fuel and oil. This incomplete combustion can produce thick, black smoke from the exhaust, indicating that the engine is burning more oil than necessary. If you notice an increase in smoke coming from your vehicle’s exhaust, it is essential to have your camshaft inspected as soon as possible.

Rough Idle

If your vehicle’s engine is running rough or vibrating excessively when at idle, it could be due to a failing camshaft. The camshaft controls the opening and closing of the valves, which affects the combustion process. When the camshaft is not functioning correctly, the engine may struggle to maintain a smooth and steady idle. If you notice your vehicle shaking or vibrating more than usual when stopped, it’s worth considering whether the camshaft needs to be replaced.

Strange Noises

Unusual noises coming from the engine compartment can also be indicative of a failing camshaft. When the camshaft is not operating correctly, it can cause the valves to open and close at the wrong time, resulting in abnormal engine sounds. These noises can range from ticking or clicking sounds to louder banging or knocking sounds. If you hear any unusual sounds coming from your engine, it is crucial to have it inspected to determine if the camshaft is the culprit.

Engine Stalling

A failing camshaft can cause your vehicle’s engine to stall or shut off unexpectedly. If the camshaft is not opening and closing the valves at the correct timing, it can disrupt the combustion process, leading to an unstable engine operation. Engine stalling can occur at idle, when accelerating, or even during driving. If you find that your engine is stalling frequently, especially without any apparent reason, it is crucial to have the camshaft thoroughly examined and potentially replaced.

Camshaft Position Sensor Issues

Sometimes, a failing camshaft may not exhibit noticeable symptoms directly related to its operation. Instead, issues with the camshaft position sensor may arise. The camshaft position sensor is responsible for monitoring the position and speed of the camshaft, providing critical input to the engine control unit (ECU). If the sensor detects any irregularities or malfunctions with the camshaft’s movement, it can trigger the check engine light and cause various performance issues. If you experience any sensor-related issues or repeated check engine light activation, it is essential to inspect both the camshaft and the sensor.


In certain cases, a failing camshaft can contribute to engine overheating. The camshaft plays a vital role in regulating the engine’s cooling system by controlling the timing of the valves. If the camshaft is not opening and closing the valves properly, it can disrupt the coolant flow, leading to inadequate engine cooling. Insufficient cooling can result in the engine temperature rising to dangerous levels and potentially causing severe damage. If you notice your engine consistently running hot or experiencing frequent overheating, it is crucial to investigate the condition of the camshaft.

Check Engine Light

The check engine light is a general indicator that something is amiss with your vehicle’s performance. While it does not specifically point to a failing camshaft, it can signal potential issues with various engine components, including the camshaft. When the camshaft is not functioning correctly, it can trigger the check engine light to illuminate. If your check engine light comes on and stays on, it is essential to have the vehicle’s diagnostic system scanned to identify any stored trouble codes. This will help pinpoint the specific cause of the issue, determining if the camshaft requires replacement or if there are other contributing factors.

Replacing a Failing Camshaft

Diagnostic Testing

Before proceeding with the replacement of a failing camshaft, it is crucial to conduct diagnostic testing to confirm the root cause of the problem. The diagnostic process may involve using specialized scan tools to retrieve any stored trouble codes, examining live data streams, and performing manual inspections. These tests will help identify if the camshaft is indeed faulty and determine if there are any other related issues that need to be addressed simultaneously.

Gathering Necessary Tools and Parts

Once you have determined that the camshaft needs replacement, the next step is gathering the necessary tools and parts. This typically includes a comprehensive socket set, wrenches, pliers, a torque wrench, a gasket scraper, a camshaft holding tool (if applicable), and a new camshaft specific to your vehicle’s make and model. It is essential to ensure that you have the correct tools and the appropriate replacement camshaft before proceeding with the replacement process.

Draining the Engine Coolant

Before removing the camshaft, it is crucial to drain the engine coolant to prevent any spills or accidents. The coolant drain plug or valve is typically located at the bottom of the radiator or on the engine block. Placing a suitable container beneath the drain outlet, carefully open the drain plug or valve to allow the coolant to flow out. Once the coolant has fully drained, securely close the drain plug or valve.

Removing the Serpentine Belt

To access the camshaft and related components, it is often necessary to remove the serpentine belt. The serpentine belt powers various engine accessories, such as the alternator, power steering pump, and water pump. To remove the belt, locate the belt tensioner and relieve the tension by using an appropriate tool, such as a breaker bar or tensioner pulley tool. With the tension released, slide the belt off the pulleys, ensuring to note the routing for reinstallation.

Disconnecting Electrical Connections

Before proceeding further, it is important to disconnect any electrical connections attached to the camshaft or camshaft cover. These connections may include wiring harness connectors, sensors, and actuators. Carefully inspect each connection and release any locking mechanisms or retaining clips as necessary. Take note of the correct position and orientation of each connector to ease reinstallation later on.

Removing the Camshaft Cover

With the electrical connections disconnected, remove the camshaft cover to gain access to the camshaft. The camshaft cover is typically secured by a series of bolts or screws. Loosen and remove these fasteners, ensuring not to damage the cover itself. Once all the fasteners are removed, gently lift the cover off the engine, taking care not to disturb or damage any associated gaskets or seals.

Removing the Old Camshaft

After removing the camshaft cover, you can now remove the old camshaft. The camshaft is secured by a series of retaining caps or brackets, which must be carefully loosened and removed. Take note of the exact sequence and position of the caps or brackets, as they need to be reinstalled in the same manner with the new camshaft. Once the retaining caps or brackets are removed, gently slide the old camshaft out of its housing, being cautious not to damage any surrounding components.

Inspecting and Cleaning Components

Before installing the new camshaft, it is essential to inspect and clean all relevant components thoroughly. Inspect the camshaft housing for any signs of damage, wear, or debris that may interfere with the proper functioning of the new camshaft. Additionally, ensure the retaining caps or brackets are in good condition and free from any defects. Clean any accumulated oil, dirt, or debris from the camshaft housing, caps, and surrounding area using an appropriate cleaner and a lint-free cloth.

Installing the New Camshaft

With the components inspected and cleaned, it is time to install the new camshaft. Gently slide the new camshaft into the housing, ensuring it aligns properly with the camshaft journals. Align the retaining caps or brackets as noted during removal and securely fasten them in the correct sequence and torque specifications specified by the vehicle manufacturer. Pay close attention to any additional installation steps or requirements outlined in the vehicle’s service manual.

Reassembly and Testing

After installing the new camshaft, it is time to reassemble the remaining components in the reverse order of removal. This includes reinstalling the camshaft cover, reconnecting the electrical connections, and reattaching the serpentine belt. Double-check that all fasteners are tightened to the appropriate torque specifications and that electrical connections are secure. Once reassembled, it is recommended to perform a thorough test of the vehicle, ensuring that the engine operates smoothly and that all issues related to the failing camshaft have been resolved.

Replacing a failing camshaft is a complex task that requires technical expertise and knowledge. If you are not confident in your abilities, it is recommended to seek professional assistance from a certified mechanic to ensure the proper replacement of the camshaft and to address any additional issues that may be contributing to the problem. Remember to follow all safety precautions and consult your vehicle’s service manual for specific instructions and guidelines relevant to your make and model.

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