Chevy AFM Problem Years (Symptoms, Causes & how to fix)

When it comes to buying reliable trucks that are good value for money, Chevrolet is one of the most dependable brands out there. The company has a long and illustrious history of making high-performance and high-reliability utility vehicles that to this day continues to fulfill customers’ expectations.

Besides performance and reliability, in the early 2000s Chevy also increased its focus on being sustainable and environmentally friendly. The company was researching heavily into finding ways to reduce the Carbon footprint of their vehicles. As a part of this initiative, Chevrolet came up with the Active Fuel Management System (AFM).

AFM was implemented in multiple Chevy truck engines from 2007 onwards to increase mileage and decrease fuel consumption. However, the system caused a lot of problems to the vehicles, starting from overconsumption of engine oil to high engine wear and tear which resulted in reduced lifespan as well as expensive repair and maintenance.

Over time the effects of the Chevy AFM problem years turned out to be way more harmful than beneficial.

Here is the short answer to Chevy AFM Problem Years

In summary, AFM is basically a fuel management system that reduces fuel consumption by shutting off half the cylinders of an engine.

In theory and testing, AFM proved to be successful. The Chevy trucks with active AFM were able to reduce fuel consumption by 5 to 7 percent.

With long periods of use, however, problems started to arise. We’ll discuss these problems in detail as we go along.

How to Tell if a Vehicle has Active Fuel Management?

In a vehicle with an AFM engine, the valley cover will have a ribbed texture on top, with its solenoids on the underside. Additionally, the back of the valley cover contains an electrical connector port.

For the non-AFM engines, the valley cover is smooth and doesn’t have any components attached to it.

Additionally, the lifters on cylinders 1,4, 6, and 7 are of a special kind. You can identify them by the springs on top.

What year did Chevy start using AFM?

Chevrolet had been researching and developing AFM for some time before introducing it to their customers. In 2007, the company finally started implementing the system in some of its engines.

AFM has been a component of Chevy engines since then. However, the Chevy Active Fuel Management problem years generally indicate the years 2007 to 2011. However, the problems continued to persist in later years.

What Chevy engines do not have AFM?

From 2007 to 2014, the following Chevy engines did not have AFM:

  • 4.3L
  • 4.8L
  • 6.2L

It must be mentioned that from 2014, all the engine options had AFM installed in them.

6 Common Chevy Active Fuel Management Problems

Oil Consumption

When AFM is active, the engines develop a problem where an excess amount of engine oil is being used up. As there is too much oil, some of it seeps into the gaps on the sides of pistons. This causes oil to enter the combustion chamber. As a result of this, the engine consumes way too much oil.

Some consumers complained that oil consumption was as high as 1 quart for every 1000 miles, which by today’s standards is extremely inefficient and expensive.


As AFM caused issues with the lifters, the engines wouldn’t be able to increase the RPMs efficiently, which would cause slower shifts between gears. In addition, the trucks would also accelerate very slowly.

Lifter Failure

Perhaps the most expensive problem caused during the Chevy AFM problem years, lifter failure was the worst-case scenario for AFM engines. As engine oil would escape through the piston gaps, the burnt oil would harden and cause damage to the lifters.

Additionally, half of the engine would go through a constant cycle of being active and inactive due to AFM, which caused issues with mechanical stress and fatigue.

Reduced Mileage

With the engine experiencing major mechanical issues, it was very normal that the engines wouldn’t last their entire expected lifetime. Trucks that were supposed to run for 150,000 started facing serious problems just after 40,000 – 50,000 miles.

Repairing the engine components is an expensive process. In some cases, owners had to pay for an entire engine replacement.

Low Power Output

Having faulty lifters, combustion chambers, and pistons due to AFM can lead to additional problems such as low power output.

Damaged engine components can cause issues such as timing issues, incorrect firing order, misfire, etc. These problems will cause the engine to not generate the ideal horsepower to the engines.

Abnormal Vibrations

The mechanical failures within the engine were reported to cause abnormal vibrations or jerks throughout the entire frame of the car, increasing the chances of structural damage or even accidents.

How do I get rid of Active Fuel Management?

Getting rid of AFM involves getting rid of or replacing the mechanical parts that actually make up the AFM system. The replacements and removals required are listed below:

  • Lifters: To begin with, you’d want to replace your factory AFM lifters with aftermarket lifters. This will prevent lifter wear and tear as well as reduce oil leaks.
  • Plug or close the pressure relief valve underneath or at the side of the oil pan.
  • Replace the factory oil pump with an aftermarket one.
  • Use a Range Technology disabler to disable the AMF system itself.
    • Make sure to keep the solenoid wires connected.
  • Replace your AMF camshaft with a non-AMF camshaft.

How to Disable AFM Without a Tune?

If you want to go for the less expensive route, disabling the AFM would definitely be the way to go.

A simple solution is to use an AFM Disabler. It’s basically an electronic device that plugs into your OBDII port to prevent AFM from taking over.

If you want to remove the programming, simply disconnect the device. The only downside is that this device doesn’t always work across all of Chevy’s AFM engines.

Can you disable AFM with a programmer?

In short, yes you can disable AFM with the help of a programmer. However, you must be very careful in doing this as a programmer will permanently alter the programming of your car, causing your warranty to become void.

How much does it cost to replace AFM lifters?

The combined cost of buying a new set of non-AFM lifters as well as a camshaft can range from anywhere between $300 and $600 without considering the charge for servicing.

In total with servicing, the cost can start from around $1000 and go up all the way up to a few thousand dollars.

people also ask (FAQs)

Will disabling AFM stop oil consumption?

In short, disabling AFM may not completely stop your truck’s oil consumption, however, it will reduce oil consumption to a great extent. This is because less oil will escape through the pistons.

It should also be mentioned here that if your engine has already developed serious issues due to AFM, disabling AFM may still not reduce oil consumption.

Will disabling AFM void the warranty?

Disabling AFM means basically using a disabling device that plugs into your car to stop AFM from functioning. As a disabler does not alter or change any of the physical components, chances are your warranty will still be valid.

However as mentioned earlier, using a programmer to completely reprogram the ECU will cause your warranty to be void.

In this case, the Range Technology Disabler might be the perfect solution for you, as it disables AFM while keeping the programming of your vehicle intact. This is by far the best method to ensure your warranty.

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Who Worked on This post?



Anderson is an experienced auto mechanic with over 10 years in the industry. He is skilled in diagnosing and repairing a wide range of vehicles, from sedans to trucks and SUV

Syed Ahmed


Syed Ahmed has been working as an auto mechanic editor for the past five years. He has a background in mechanical engineering and a love for all things automotive

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