What Is A Lifter On A Car?

You turn the key in your Ford, and you can hear is a rapid tapping noise. What could be wrong with your engine? If you’ve got an engine with pushrods, it’s likely that one of your valve lifters has gone bad or is out of adjustment.

So, what is a lifter, and what exactly does it do? Let’s take a closer look.

What Is A Lifter On A Car?

A lifter is a cylinder that sits between a car’s camshaft and the cylinder valves. As the camshaft moves over the top of the lifter, it actuates, temporarily opening the valve. And because the intake and exhaust valve need to open at different times, each has its own separate lifter.

Lifters can be designed differently, depending on the vehicle. For example, lifters on pushrod engines activate a rocker arm instead of directly pressing on the valve.

What Is A Lifter On A Car

Lifters in OHV Engines

Traditionally, the term “lifters” has been used to describe the components in an overhead valve (OHV) engine that follow the contours of the camshaft. As the camshaft rotates, the lifters act on a series of pushrods, which, in turn, operate the rocker arms to open and close the engine’s valves. The lifters also maintain the engine’s valvetrain lash (clearance).

Lifters can be either solid (mechanical) or hydraulic. With solid lifters, valvetrain lash must be adjusted mechanically from time to time. On the other hand, hydraulic lifters rely on pressurized engine oil to automatically adjust lash internally, so there’s no need for periodic adjustment.

What’s more, there are flat lifters (tappets) and roller lifters. Flat lifters, which are typically found in vintage vehicles, have a relatively flat face that slides on the camshaft. Meanwhile, roller lifters have a wheel-like roller that follows the camshaft’s outline. Since the 1990’s, nearly all OHV engines have come with roller lifters.

Lifters (Lash Adjusters) in OHC Engines

These days, the hydraulic lash adjusters found in overhead camshaft (OHC) engines may also be referred to as lifters. The lash adjusters correct the clearance between the valvetrain components. Depending on the engine’s design, each lash adjuster may be located between the cylinder head and a camshaft follower, inside of a bucket over the valve, or built into the rocker arm.

Why Are Valve Lifters Important?

Valve lifters help to control the combustion process by letting fuel in, and exhaust out. When valve lifters wear out, your valves can’t open or close properly. This reduces the amount of power the engine can produce. When one of your valve lifters goes bad, one of the two scenarios can happen:

  • If the lifter is connected to an exhaust valve, the valve can’t get rid of the fuel/air mixture
  • If the lifter is connected to an intake valve, the fuel/air mixture can’t get into the combustion chamber

Either way, it throws off the engine’s valve timing, and the engine won’t run as well as it should.

How does the Valve Lifter Work?

The basic function of a valve lifter is pretty simple. It sits on the camshaft and transfers the motions of the cam lobe up through the pushrods and rockers to open and close the valves.

The size and shape of the cam lobe under the lifter (multiplied by the ratio of the rocker arms) determines valve lift and duration. As such, the lifter just follows the motions of the cam. But it does play a role in valvetrain lash (clearance) and noise.

So, How does the Valve Lifter Actually Work? The camshaft has various egg-shaped cam lobes on it. There are mainly two valves in pushrod engines and 16 lobes on the camshaft. The lower end of each valve lifter sits on a cam lobe. With the camshafts spinning, the cam lobes move, causing the lifters to move up and down.

The top end of each pushrod positioned on a lifter pushes upward on a rocker’s arm. As the pushrods push upward on the rocker’s arm, its other end moves downward at the top of the valve stem, leading to the valve’s opening in a downward direction.

Each cylinder usually has two valve stems: the exhaust valve stem that releases the air mixture from the combustion chamber and the intake valve stem that brings the air into the chamber.

Simply put, a valve lifter transfers the motion of the cam lobes to the rocker arm/ pushrods to open and close the valve. They are crafted in very specific dimensions and are neither too long nor too short. Their correct size is very important for the opening and closing of the valve lifter.

Types of lifters

That said, lifters fall into two types: hydraulic or mechanical. Let’s take a look at both.

Hydraulic Lifters

First invented in the 1930s to reduce the noise from older mechanical lifters, hydraulic lifters are the most common variety of lifter on the market. However, because of their higher cost, they didn’t enter the mass market until the 1950s.

Hydraulic lifters consist of a cylindrical body with an internal piston that protrudes from the top. Here’s how they work:

  • Pressurized oil enters through a hole in the lifter body and flows into a narrow channel. This oil enters the internal lifter cylinder but flows freely out the other side.
  • When the cam presses down on the lifter piston, it closes the channel. This locks the valve open temporarily, even under high pressure, so that gas can escape the cylinder.
  • When the cam passes its apex, the lifter piston can rise, allowing the oil to flow freely again. In turn, it causes the valve to snap shut, preserving proper engine air pressure.

The floating piston design aims to reduce valve lash, or the gap between the rocker arm and the valve tippet. Larger amounts of lash are more forgiving but can cause rattling and knocking. The less the lash, the quieter and smoother the ride.

A good set of hydraulic lifters will reduce valve lash to about 0.006 inches. That’s an incredibly tiny amount of space.

The problem here is that the lifter must operate to precise tolerances in order to do its job. If the engine RPMs are too high, the oil won’t have time to fully re-pressurize the valve, leading to reduced airflow and poor performance.

Conversely, a hydraulic lifter that becomes over-pressurized can fail to close the valves all the way. This will create leakage and can cause damage if the valve is too far open and prevents ignition.

Mechanical Lifters

Hydraulic lifters were in their heyday from the 1950s through the 1980s, when they were found in nearly every car on the road. However, some newer vehicles have started using mechanical lifters again.

They might be louder, but mechanical lifters have a couple of distinct advantages over their hydraulic counterparts. First, they’re cheap and low-maintenance, so they’re great for economy cars. They’re also useful for performance cars because they work reliably at higher RPMs.

There are two main types of mechanical lifters: solid lifters and roller lifters. A solid lifter is precisely what it sounds like: a solid metal cylinder. As the cam rotates, it either presses down on the cylinder or allows it to rise.

Roller lifters have a similar design but are engineered to mitigate the noise from solid lifters. Instead of a flat back, they have rollers on the back that allow the cam to rotate smoothly over the top.

This significantly reduces noise and improves performance, particularly at higher RPMs. On the other hand, the rollers are higher maintenance than an ordinary solid lifter, leading to higher mechanic bills in the long run.

What Are The Symptoms Of A Faulty Engine Lifter?

To identify whether there is a defect in the engine lifters, there are certain signs and symptoms. Some of these are mentioned here:

It does not always indicate that the above symptoms indicate engine lifter failure, but if you notice two or more of these symptoms, you should check your vehicle.

How Can You Quiet Your Car Engine?

Once you verify the lifter ticking is not caused by a worn-out lifter or some other damaged part, the best thing to do is change the oil. Get rid of all the oil currently in the engine and flush it out before adding new oil. Make very sure the new oil you are putting in is exactly the type of oil the manufacturer specifies. If you can, make sure it is synthetic oil. If you can’t get synthetic oil, at least use a synthetic blend.

Once you change the oil, let the car run for a half-hour or so to help the oil work its way through the system. If the lifter noise was from an oil problem, you should find it goes away after you do this.

If this does not resolve the problem, try again to see if you have a parts issue. Make sure the pushrods are straight, the rocker arm is properly attached and the lifters themselves appear undamaged.

You can also adjust the valve lash, which is the space between the rocker arms and the valves, tightening or loosening as necessary. Hydraulic valve lifters are self-adjusting, but if nothing else is working, this might provide the solution. Admittedly, these are things many people can’t do without the expertise of a mechanic.

How Much Does a Lifter Replacement Cost?

There are about 8 to 16 lifters in most of the cars. If you find a defect on any of these, you should replace the lifters all at once instead of replacing them at different times. Each of the engine cylinders in a car has two cylinders that are joined to the valves. 

If there are eight cylinders, it costs a total of $1600 to $2,200; six cylinders cost around $1100 to $1,750, while four cylinders cost $900 to $1,500. 

A skilled mechanic would charge you $60-$150 per hour to replace the faulty engine lifters.

Replacing one or more lifters is a costly and labor-intensive repair. If you choose to have a professional do the job, you can usually expect to pay somewhere between $1,000 and $2,500 to get the job done. Of course, the exact cost will depend on various factors, such as the year, make, and model of your vehicle.

To save money, you can do the replacement job yourself if you have adequate knowledge.

What to Do If You Have a Faulty Hydraulic Lifter?

If your car has a faulty hydraulic lifter, replace it as soon as possible to avoid further damaging your engine.

In most cases, a faulty hydraulic lifter will simply need to be replaced. You might be able to get away with replacing a single bad hydraulic filter depending on the make and model of your vehicle. However, many mechanics suggest that when replacing one lifter, you should go ahead and replace them all, because it’s generally a good indication that others will soon fail.

Depending upon the age of your vehicle, you might consider using refurbished lifters in your vehicle rather than purchasing new ones. Refurbished hydraulic lifters will cost a lot less money and will usually do an adequate job for older used vehicles, which may not have many more years of service left in them.