Does My Engine Need a Valve Clearance Adjustment?

Taking care of your vehicle is vital to ensure it stays in great condition. Your brakes could give you trouble someday, or your suspension could require tinkering, inevitably leading you to an auto shop or an independent mechanic. 

The most crucial part of your car is the engine. It is responsible for your vehicle’s movement, and you should pay close attention to all its parts, including the valves. 

In this article, we will talk about getting valve clearance adjustments. We will start with explaining how your engine works, then get to the valves themselves, talk about the frequency of the procedure, and end on signs that show your valves need to be tinkered with. 

How Does The Engine Work?

An internal-combustion engine is a heat engine that converts energy from the heat of burning gasoline. When all is over, the burning gasoline turns into mechanical work, or torque, which applies to the wheels and creates vehicle movement.

Engines have pistons that move up and down inside metal tubes (cylinders). They, in turn, connect with the crankshaft that spins with their help. There may be between two or twelve cylinders with the corresponding number of pistons depending on the vehicle. 

All modern engines go through a specific cycle: combustion, intake, compression, and exhaust. Combustion pushes the pistons down from the top of the cylinder. As engines need air to burn fuel, during intake, valves open up and allow ambient air to come in. When the piston reaches the bottom, the valves close for compression, and it is then sent upward to absorb the intake charge. After that, what remains goes out of the car through the exhaust system. 

Valves: Different Types And How They Work

Generally speaking, valves look like inverted golf t-shirts and closely interact with rotating camshafts in your engine. They open and close depending on the rotation of the cam or its lobes. There are two types of valves in your engine: intake and exhaust. The first ones are responsible for letting in the air-fuel mixture for the cylinders, while the latter allows the produced gas to escape the vehicle afterward.

The clearances between the lobes and the intake valves can increase with extended time and use and lead to problems. Exhaust valves go the other way around, and the clearance becomes tighter. It causes small and relatively unnoticeable issues for your car that only a trained eye can catch. 

Signs That You Need Valve Clearance Adjustment

As the valves are within your engine, all the symptoms will be connected with it. As such, you may experience the following:

• Cluttering noises. The clearance is too large, and the pushrods don’t work smoothly. Usually, it will be either cluttering or increased engine vibration that will only strengthen with time. 

• Rough idling. If the valves don't open the intake and exhaust at the right time, it will restrict airflow into the engine, which may manifest as rough idling.

• Oil consumption. You may notice the level going down on your dipstick. At this stage, consider servicing your vehicle as soon as possible. 

Whenever you notice any of these signs, you need a valve adjustment. You shouldn’t delay the required repairs or maintenance as that could lead to excessive damage to your engine and horrible news for your finances. 

Summary

How often should you adjust the valve clearance? It depends on your particular situation. If you are just wondering about frequency and notice no symptoms, then every 60,000 miles or so. But it's time for action when you hear cluttering and experience rough idling or oil consumption. 

Auto shops or mechanics charge around $150-$300 for the adjustment, but it depends on the make and model of your car. The process would involve removing the valve cover and measuring the space between intake and exhaust valves and their lobes with feeler gauges. Adjustments can take a lot of time and may even include shim replacement as part of the procedure. So, expect to pay for a few hours of labor and the inspection charge. 

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