What is a Camshaft and Why Is It So Important?

You’ve probably heard of the camshaft before, but do you really know what it does? At Sandicliffe, we believe that understanding the key components of your vehicle can help you spot issues early and keep your car running smoothly.

In this guide, we’ll explain what a camshaft is, how it works, the different types available, and the most common problems to watch out for.

What Is a Camshaft?

The camshaft is a vital component in an internal combustion engine. Its main job is to control the opening and closing of the intake and exhaust valves in the cylinder head. This process allows air and fuel into the engine and lets exhaust gases escape, ensuring the engine runs efficiently.

Without a properly functioning camshaft, the engine simply wouldn’t work. The camshaft consists of a shaft fitted with cams (lobes), and its performance depends heavily on the quality of its materials, condition, and lubrication.

How Does a Camshaft Work?

The camshaft works in close coordination with the crankshaft. It is connected via a timing belt or timing chain and rotates as the crankshaft is driven by the pistons.

As the camshaft rotates, the cams push against valve components to open and close the intake and exhaust valves at precisely the right moments. Correct timing is essential, even a small misalignment can lead to reduced performance or serious engine damage.

Originally, camshafts were designed simply to manage valve timing. Modern designs, however, have evolved to improve engine power, fuel efficiency, and emissions.

Types of Camshafts

There are several camshaft configurations used in modern vehicles, depending on engine design and performance requirements:

• Single Overhead Camshaft (SOHC)
  This is the simplest and most common design. A single camshaft operates both the intake and exhaust valves.

• Double Overhead Camshaft (DOHC)
  This system uses two camshafts – one for intake valves and one for exhaust valves. It allows for better airflow, improved performance, and greater fuel efficiency.

• Mechanical or Valve-Piston Locking Systems
  These more complex systems optimise valve timing by closing valves before the piston reaches top dead centre. While effective, they are typically found in higher-performance or more advanced engines.

Common Camshaft Problems

Like any engine component, camshafts can wear over time. Some of the most common issues include:

• Cam or bearing wear
  This can cause abnormal engine noises and reduced performance, often due to poor lubrication or age.

• Timing belt or pulley issues
  Excessive wear can lead to incorrect valve timing, which may result in engine damage if left unchecked.

• Overheating due to lack of lubrication
  Oil seals and gaskets play a crucial role in keeping the camshaft lubricated. If these fail, friction and heat can cause serious damage.

• Low engine oil levels
  Insufficient oil prevents proper lubrication, accelerating wear on camshaft bearings and cams. Always maintain oil levels according to the manufacturer’s recommendations.

When Does a Camshaft Need Replacing?

Replacing a camshaft is a complex job that requires specialist tools and expertise, so it’s best handled by a qualified technician.

You may need to have your camshaft inspected or replaced if you notice:

• Unusual engine noises

• Loss of power

• Difficulty starting the engine

• Warning lights on the dashboard

While the exact replacement process varies by engine type, it typically involves removing the valve cover, aligning the crankshaft, carefully replacing the camshaft, and ensuring everything is correctly timed before reassembly.

Need Expert Advice?

If you’re experiencing engine issues or would like professional guidance, Sandicliffe’s trained technicians are here to help. Regular servicing and early inspections can prevent costly repairs and keep your vehicle performing at its best.