Updated at: 14-08-2022 - By: Lucas

An active fuel management system, often known as AFM, controls how much power the engine’s cylinders consume, which results in better fuel economy. However, this can lead to AFM lifter failure and high oil consumption, so use with caution. Some of our readers have inquired regarding troubles with the chevrolet 6.0 lifter with the 5. 3 AFM. What causes AFM lifter failure, how to prevent it and how to stop it without a tune are all covered in this post, as well.

How the AFM System Works

Fuel consumption is decreased by switching off half of your engine cylinders in low-load and cruise driving circumstances using the Active Fuel Management (AFM) system. Fuel mileage can be improved by 5–7 percent with AFM, as evidenced by research studies.

AFM Lifter Failure Symptoms

Internal functioning processes of the AFM system must be turned on and off thousands of times to function properly. When this happens, the AFM lifter is likely to fail.

AFM Lifter Failure Symptoms

Faulty Because AFM lifters can do serious harm to your vehicle, it’s critical to catch a malfunction as soon as possible. The following are signs that your AFM lifter is failing:

1. Difficulty in Downshifting

If you find it difficult to downshift while driving, you may have a problem with your car’s AFM lifters. Taking immediate action is critical because this can cause serious damage to the vehicle’s clutch, flywheel, and potentially the transmission system.

2. Low Engine Power

However, if your engine fails to deliver maximum power when needed, this could be a sign of AFM lifter failure. Lifter failure is not ruled out as a cause of this issue despite other possibilities, such as engine timing or misfire.

3. Vehicle Jerking When Accelerating

An AFM lifter failure might result in your car jerking from side to side when you accelerate without notice. If it isn’t fixed very away, it could be a serious safety threat and lead to significant damage.

4. Vehicle Hesitating When Accelerating

If your automobile hesitates when accelerating, an AFM lifter failure could be the cause. Other issues such as excessively high temperatures or a faulty mass airflow sensor may be at blame. Don’t put it off and get it looked out as soon as possible, whatever the cause may be.

5. Sudden Stalling

AFM lifter failure can cause an automobile engine to suddenly stall without notice. When the engine is grinding and sputtering, the car is in grave danger of stalling. A sudden stall in the middle of the road while driving can be extremely dangerous, resulting to a complete loss of control. Get your car checked out right away if you experience this symptom.

What Are the Causes of AFM Lifter Failure?

AFM Lifter Failure Symptoms-2

AFM lifter failure can represent a serious road hazard if left uncorrected, therefore it’s important to recognize both the signs and causes of this problem. The following are examples of issues that have been discovered:

1. Low Oil Levels

The AFM lifter, like all other engine components, requires regular maintenance, and a shortage of oil can lead to major issues. Low oil levels can cause AFM lifter failure because the engine’s moving parts create too much friction, generating indents in the oil seals and subsequently the failure of the lifters.

2. Poor Quality Oil

Low-quality oil is a common cause of AFM lifter failure. Bad quality oil can cause complete AFM lifter failure, necessitating a complete engine overhaul and possibly rerouting stock tanks, if used for an extended period.

3. General Wear and Tear

AFM lifters eventually fail due to wear and tear from regular operation. If this wear and tear is not addressed, the engine components will degrade steadily over time.

How Do I Prevent AFM Lifter Failure?

There are a few things you can do to avoid AFM lifter failure and further harm to your car’s engine. They include:

1. Use High-Quality Oil in Your Vehicle

For the most part, it’s not necessary to shell out for the most costly oil on the market in order to keep your engine running smoothly. An AFM lifter failure can now be avoided.

2. Service Your Car Regularly

Regular auto maintenance, such as a trip to the mechanic, is a great approach to prevent AFM lifter failure due to normal wear and strain. This will catch any emerging issues early on and may even help to prevent problems that are yet to arise.

3. Use an AFM Disabler

Because the AFM system prevents half of your engine’s cylinders from operating to control fuel consumption, AFM lifter failure is the primary cause of AFM lifter failure. By disabling the AFM so that it doesn’t work as often, you can significantly reduce the risk of AFM lifter failure. The AFM disabler may be activated in a matter of seconds and will extend the life of the lifters.

How to Disable AFM Without a Tune

AFM Lifter Failure Symptoms-3

There are two ways to turn off AFM in your car without voiding your warranty, whether it’s to avoid AFM lifter failure or for any other reason.

1. Removing the Brake Booster Vacuum Sensor

Remove the vacuum sensor from the brake booster assembly to disable the AFM. However, the Check Engine light may illuminate as a result, which can be troublesome.

2. Using an AFM Disabler

AFM disablers can also be used to disable an AFM without a tune. Installing, activating, and uninstalling this program couldn’t be easier. Once you’ve removed the AFM from the OBD2 port, everything should go back to the way it was.


What causes AFM lifters to collapse?

Lifter failures in AFMs are most commonly caused by low oil pressure, the use of low-quality oils, or wear and tear.

How Do I Know if My AFM Lifter is Bad?

The most common signs of an AFM lifter collapsing are as follows:.

Downshifting is difficult, acceleration is jerky, the engine power is low, and the car suddenly stalls.

Can I Disable My AFM Without Tuning It?

Definitely. Using an AFM disabler or removing the vacuum sensor from the brake booster should do the trick here.

Should I Disable AFM?

In order to avoid AFM lifter failure and maximize the performance of your car’s engine, you should disengage AFM.

Will Disabling AFM Save Lifters?

As the lifters will be used less frequently and hence have less wear and tear, eliminating AFM can save them from failure.

How Can I Prevent AFM Lifter Failure?

You may avoid AFM lifter failure by following a few simple procedures. They are, for example. utilizing engine-specific oil, disabling AFM with an AFM disabler, and having your car serviced on a regular basis are all good ideas.


Failure of the AFM lifter is a typical occurrence in automobiles and can affect any model. The problem can be caused by a variety of factors, which we have outlined in depth.

Some procedures, like as replacing the malfunctioning AFM lifter or even disabling AFM, can be taken to permanently fix this issue.