AFM Lifters: Symptoms And Causes Of Failure

AFM Lifters: Symptoms And Causes Of Failure


April 8, 2022

This is a function that controls the engine’s cylinders’ power consumption, resulting in improved mileage. This can have drawbacks, however, since it might induce AFM lifters to collapse and excessive oil usage.

Several of our visitors have inquired regarding Chevy 6.0 lifter failure rates and 5.3 AFM failure occurrences.

We’ll go through everything there is to know about the problem, including the reasons for lifter failure, the way to stop it, and the method of turning off the AFM if necessary.

The AFM System’s Functionality

AFM Lifters: Symptoms And Causes Of Failure

When your vehicle’s Active Fuel Management (AFM) system is in low load and cruising driving modes, it shuts off half of the engine cylinders to enable it to run at a lower power status and save fuel.

According to studies, AFM can increase fuel efficiency by 5 to 7 percent.

To spin on and shut off hundreds of units, the internal working mechanisms of the AFM system must be in constant use millions of times a day. This can result in considerable wear and, ultimately, failure of the lifter.

Symptoms Of An Andover Air Products AFM Lifter Failure

AFM Lifters: Symptoms And Causes Of Failure

Because broken AFM lifters can do significant harm to a car, it’s critical to discover them early. The following are some of the warning signals that AFM lifters may be failing:

It’s Difficult To Downshift

If you have trouble downshifting, the AFM lifters in your automobile may be harmed. It is critical to take immediate action once you detect this since it can lead to significant parts of the automobile’s engine, such as the clutch and flywheel, failing.

Extremely Meager Engine Power

If your engine doesn’t have enough power when you need it, there might be a problem with the AFM lifters. It’s possible that the engine yields to generate adequate power because the AFM lifter has failed.

While problems with engine timing and cylinder misfiring are conceivable reasons, don’t rule out the possibility of an AFM malfunction.

When Accelerating, The Car Jerks About.

When your car shudders from sides as soon as you put it into gear and accelerate, the AFM lifters have likely given out. If left untreated, this condition can cause significant property damage and physical harm. 

When Accelerating, The Car Hesitates

If your car seems to hesitate when you accelerate, the AFM lifters have failed. It might be a sign of something else, such as overheating or a multitude of airflow detector failures. No matter, what the reason is, don’t ignore it; get it looked at right away.

Hasty Stalling

When an engine begins stalling suddenly, it’s a sure sign that the AFM lifters are failing. This, along with the sounds of metal on metal, is highly dangerous since the vehicle could delay at any time.

When the engine stalls in the middle of a road, causing a failure of control and putting you and your passengers in danger, this may be quite deadly. If you detect any of these indicators, have your car examined as soon as possible.

What Causes Lifter Failure?

AFM Lifters: Symptoms And Causes Of Failure

Aside from understanding what warning signals indicate that the lifter is about to fail and how it might be a hazard if unattended, you should also be aware of the reasons for this trouble. The following are some of the issues that are linked to AFM:

Lower Oil Levels

The AFM lifters, like any other engine component, require adequate lubrication to operate effectively. Inadequate oil to deliver the necessary lubrication might create serious difficulties.

Excessive friction in the engine’s moving components may lead to oil seal indents and eventually lifter failure if your car’s oil levels are kept too low for an extended period of time.               

Inferior Quality Oil

Low-quality oil is one of the grounds for AFM lifters’ failure. If you utilize a low-quality oil for an extended period of time, your engine’s AFM lifters could collapse, necessitating the replacement of many components.

Normal Wear And Tear

When regular usage is applied to an engine, the components wear down with time, and if this wear and rip are not reversed, an AFM lifter failure will occur.

How Can I Control AFM Lifters Failure?

AFM Lifters: Symptoms And Causes Of Failure

There are a few things you may do to prevent your engine from failing and causing additional damage. They are as follows:

Use High-Quality Oil In Your Automobile.

You don’t have to spend a lot of money on the most pricey oil on the market, but make sure it’s from the manufacturer or is extremely closely matched to the engine. This may assist in preventing lifter AFM failure.

Regularly Service Your Car

If your car has an “AFM lifters’ failure mileage” of 20,000 miles or more, it should be serviced twice a year and the components replaced as needed.

This is an excellent technique to avoid lifter failure in the long run by eliminating ordinary wear and tear. Take care of your vehicle on a regular basis by having it serviced.

Use A Tool To Disable The AFM.

The most common cause of AFFM failure is the AFM shutting off half of your engine’s cylinders to regulate fuel usage. You may significantly minimize the chances of AFM lifters’ failure by turning off the AFM.

Turning on the AFM disabler is simple and gives you the added benefit of ensuring that the lifters operate correctly.

How To Turn Off AFM Without A Tuner

If you like to turn off AFM on your car for whatever reason, whether it’s due to lifter failure or anything else, there are two options:

The Brake Booster Vacuum Sensor Must Be Removed

The AFM will be disabled if you take the vacuum sensor out of the brake booster assembly. However, it may cause the “Check Engine” indicator to come on, which can be inconvenient.

Disabling The AFM With An AFM Disabler

An activated AFM is sometimes difficult to deactivate because it’s already on, so a disabler might be necessary. It’s simple to set up, operate, and remove. When you remove the AFM from the OBD2 port, everything should return to normal.


What Is The Cause Of AFM Lifters Collapsing?

The most common reasons for AFM lift failure are low-quality oils, faulty maintenance, and general wear and tear.

What Should I Look For When Shopping For AFM Lifters?

The presence of an AFM lifter collapse is difficult to detect because there are so many symptoms. The most prevalent ones are difficulty in downshifting, jerky acceleration, low engine performance, and sudden stopping.

Is It Possible To Get Rid Of My AFM Without Tuning It?

Yes, it’s possible. You may either turn off the AFM or eliminate the brake booster vacuum sensor in order to do so.

Should I Turn Off AutoFocus?

If you don’t want your car’s engine to catastrophically fail, or if you just want it to run at maximum efficiency, AFM should be disabled.

Does It Make A Difference If I Disable AFM?

Yes, reducing the number of times you use your AFM lifters can help you avoid failure since if you don’t get it all time, it will be used less frequently and so will get less wear and tear.

How Can I Avoid AFM Lifters Failure?

There are a few things you can do to avoid the AFM lifters from failing. They include using engine oil designed for your car, disabling AFM with an AFM disabler, and maintaining your vehicle on a regular basis.


An AFM lifters failure, which may affect any vehicle, is the topic of this article. The issue might have a variety of causes and has been listed and clarified in detail.

To permanently repair this issue, you may just replace the faulty lifter or even turn off AFM.


Jeffrey Bryce is an experienced motorcycle rider with years of experience caring for motorcycles. His natural fondness for motorcycles have made him come up with, which is dedicated to answering and teaching you how to care for your bike with the care it requires. LetsGoForARide is the one of his important lifework in reaching out to communities of motorcycle enthusiasts on how to take care of their bike and choosing the correct spare part.