Valve Adjustment: The Essential Tune-up for a Healthy and Happy Engine

If you own a vehicle, you probably know that regular maintenance is essential to keep it running smoothly and efficiently. One of the most important maintenance tasks that you should not overlook is valve adjustment. In this article, we will explain what valve adjustment is, why it is important, how to do it, and what benefits it can bring to your engine.

What is valve adjustment?

Valve adjustment is the process of setting the correct gap between the valves and the rocker arms or camshafts in your engine. Valves are the components that open and close to allow air and fuel to enter and exit the combustion chambers. Rocker arms or camshafts are the components that push or pull the valves to open and close them.

The gap between the valves and the rocker arms or camshafts is called valve clearance. Valve clearance is measured in thousandths of an inch or millimeters. Valve clearance is not constant; it changes over time due to wear and tear, temperature changes, and engine operation.

Why is valve adjustment important?

Valve adjustment is important because it affects the performance, efficiency, and longevity of your engine. If the valve clearance is too tight or too loose, it can cause several problems, such as:

• Poor engine performance: If the valve clearance is too tight, the valves may not open fully or close properly, resulting in reduced airflow and fuel delivery to the combustion chambers. This can cause loss of power, rough idle, misfires, and engine noise. If the valve clearance is too loose, the valves may open and close too early or too late, resulting in improper timing and compression of the air-fuel mixture. This can cause poor fuel economy, increased emissions, and engine damage.
• Increased wear and tear: If the valve clearance is too tight or too loose, it can cause excessive friction and stress on the valves, rocker arms, camshafts, and other engine components. This can lead to premature wear and tear, increased oil consumption, and reduced engine life.

Signs that your engine may need a valve adjustment

Some of the signs that your engine may need a valve adjustment are:

1. Engine noise: You may hear a ticking, tapping, clattering, or knocking sound from your engine when it is running. This is caused by the valves hitting the rocker arms or camshafts with too much or too little force.
2. Hard starting: You may have difficulty starting your engine or experience longer cranking time. This is caused by the valves not sealing properly or not opening at the right time, resulting in low compression or poor ignition.
3. Poor performance: You may notice a decrease in power, acceleration, responsiveness, or smoothness of your engine. This is caused by the valves not allowing enough air and fuel to enter or exit the combustion chambers, resulting in incomplete combustion or detonation.
4. Check engine light: You may see a check engine light on your dashboard indicating an error code related to your valves. This is caused by the sensors detecting abnormal readings from your valves. 

If you notice any of these signs, you should take your vehicle to a mechanic for a valve adjustment as soon as possible.

Types of valve adjustment

There are different types of valve adjustment depending on the type of valve lifters in your engine. Valve lifters are the components that connect the valves to the rocker arms or camshafts. There are three main types of valve lifters:

• Hydraulic valve lifters: These are self-adjusting valve lifters that use oil pressure to maintain a constant valve clearance. They do not require manual valve adjustment unless they are damaged or worn out. 
• Solid valve lifters: These are non-adjustable valve lifters that have a fixed valve clearance. They require periodic manual valve adjustment to compensate for wear and tear and temperature changes.
• Shim-under-bucket valve lifters: These are adjustable valve lifters that use thin metal discs called shims to set the valve clearance. They require occasional manual valve adjustment to replace worn or incorrect shims. 

You can find out what type of valve lifters your engine has by consulting your owner’s manual or asking a mechanic.

Tools and equipment needed for valve adjustment

To perform a valve adjustment on your own, you will need some tools and equipment, such as:

• Feeler gauges: These are thin metal blades of different thicknesses that are used to measure the gap between the valves and the rocker arms or camshafts. 
• Wrenches: These are used to loosen and tighten the nuts or bolts that hold the rocker arms or camshafts in place.
• Screwdrivers: These are used to adjust the screws that control the valve clearance on some engines.
• Torque wrench: This is used to apply a specific amount of force when tightening the nuts or bolts that hold the rocker arms or camshafts in place.

You will also need some safety equipment, such as gloves, goggles, and a fire extinguisher.

How to adjust valves

The procedure for adjusting valves may vary depending on the type of engine and valve lifters you have. However, the general steps are as follows:

• Locating the valve clearance specifications: You will need to find out the correct valve clearance for your engine. You can find this information in your owner’s manual, on a sticker under the hood, or online. The valve clearance may be different for the intake and exhaust valves, and for cold and hot engines. 
• Measuring valve clearance: You will need to measure the gap between the valves and the rocker arms or camshafts using feeler gauges. To do this, you will need to remove the valve cover, rotate the crankshaft until the piston is at top dead center (TDC) for each cylinder, and insert the feeler gauge between the valve and the rocker arm or camshaft. The feeler gauge should slide in and out with a slight drag. If the gap is too tight or too loose, you will need to adjust it.
• Adjusting valve clearance: You will need to adjust the gap between the valves and the rocker arms or camshafts using wrenches, screwdrivers, or shims. To do this, you will need to loosen the nut or bolt that holds the rocker arm or camshaft in place, adjust the screw or shim that controls the valve clearance, and tighten the nut or bolt to the specified torque. You will need to repeat this process for each valve until they are all within the correct range.

Tips for valve adjustment

Here are some tips to help you perform a successful valve adjustment:

1. Follow the correct procedure: Make sure you follow the steps and instructions for your specific engine and valve lifters. Do not skip any steps or make any assumptions.
2. Use the correct tools and equipment: Make sure you use the right tools and equipment for your valve adjustment. Do not use tools that are worn out, damaged, or incompatible with your engine.
3. Be patient and take your time: Do not rush or force anything when adjusting your valves. Take your time and check your work carefully. If you are not sure about something, ask for help or consult a professional.

Benefits of valve adjustment

By regularly adjusting your valves, you can enjoy several benefits, such as:

1. Improved engine performance: By ensuring that your valves open and close at the right time and with the right force, you can improve the airflow and fuel delivery to your combustion chambers. This can result in more power, smoother idle, better acceleration, and less noise from your engine.
2. Reduced fuel consumption: By optimizing the combustion of your air-fuel mixture, you can reduce the amount of fuel that is wasted or unburned. This can result in better fuel economy and lower emissions from your engine.
3. Extended engine life: By reducing the friction and stress on your valves, rocker arms, camshafts, and other engine components, you can prevent premature wear and tear, oil leaks, and engine failure. This can result in longer engine life and lower maintenance costs.

How often should you adjust your valves?

The frequency of valve adjustment depends on the type of engine and valve lifters you have, as well as the driving conditions you encounter. Generally speaking, hydraulic valve lifters do not require regular valve adjustment unless they are damaged or worn out. Solid valve lifters require periodic valve adjustment every 10,000 to 20,000 miles or every 12 to 24 months. Shim-under-bucket valve lifters require occasional valve adjustment every 30,000 to 60,000 miles or every 36 to 48 months.

However, these are only general guidelines. You should consult your owner’s manual for the recommended valve adjustment interval for your specific vehicle.

Can you adjust your own valves?

Yes, it is possible to adjust your own valves if you have the necessary tools, equipment, and knowledge. However, if you are not comfortable performing this task, it is best to take your vehicle to a qualified mechanic who can do it for you.

Valve adjustment is an important part of engine maintenance that can help you keep your vehicle running at its best. By following this article, you can learn more about what valve adjustment is, why it is important, how to do it, and what benefits it can bring to your engine.

Dangers of improperly adjusted valves.

• Improperly adjusting your valves can cause serious damage to your engine and other components.
• Do not attempt to adjust your valves if you are not confident in your skills or knowledge.
• Do not adjust your valves when your engine is hot or running.
• Do not force anything when adjusting your valves.
• Do not over-tighten or under-tighten any nuts or bolts when adjusting your valves.

How to Avoid Common Mistakes When Doing Valve Adjustment

• Follow the correct procedure for your specific engine and valve lifters.
• Use the correct tools and equipment for your valve adjustment.
• Be patient and take your time when adjusting your valves.
• Check your work carefully and recheck your valve clearance after adjusting it.
• Consult your owner’s manual or a professional mechanic if you have any questions or doubts.

Don’t forget to share it