Active Fuel Management is typically reserved for larger GM vehicles with V-6 or V-8 engines. In vehicles with V6 engines, the technology temporary turns the vehicle into an inline V-3 engine. V-8 engines are momentarily reduced to V-4 performance.
Active Fuel Management (AFM) was a system GM engineers developed back in 2005 to help improve the fuel mileage from some of their V6 and V8 engine applications. AFM shuts off half of your engines cylinders to operate at a reduced power level to reduce fuel consumption when running in low load and cruise situations.
How does AFM work in a car?
AFM works by closing the intake and exhaust valves on up to four-cylinders under certain driving conditions. Vehicle speed and torque delivery are maintained by utilising the engine’s electronic throttle control to increase cylinder pressure in V4 mode.
Unfortunately, it causes a number of issues for the Vortec engine family. The 5.3, 6.0, and 6.2 vortec engines that are equipped with AFM are known to have lifter failure, oil life monitoring system issues, and excessive oil consumption.
What engines have AFM? – Related Questions
Can dealer turn off AFM?
Most dealerships do not have the software to turn off AFM. Correct. Dealers can not “custom” modify your software nor would they want to.
How do you prevent AFM failure?
Check your oil
Oil pressure issues, oil quality issues, and simply running out of oil can all be causes of problems with your AFM. The best and most simple way to prevent AFM lifter failure is to check your oil regularly; ensure that it is full enough, and conduct an oil change if it’s not.
Does AFM cause lifter failure?
Most people rarely need to use 100% of their engine’s horsepower, especially in big V8 motors. AFM allows the car to “turn off” half the valves to their respective cylinders while the engine’s running. With fewer firing, you can get better mpg – up to 7% more. The AFM lifters – essential to the process – can fail.
Will turning off AFM void warranty?
Because no tuning is involved with your vehicle’s computer, this product will not void the factory warranty. Not only does the AFM Disabler keep your vehicle running smoothly, but it will also have you running on all cylinders, all the time.
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.
What year Silverados have lifter problems?
More specifically, the GM lifter problems affect both the 2019-2021 Chevrolet Silverado and GMC Sierra pickups as well as their GMT T1XX platform SUV siblings — the Chevrolet Tahoe, Chevrolet Suburban, GMC Yukon and Cadillac Escalade.
How do I know if my AFM lifter is bad?
If an AFM lifter is mechanically collapsed/stuck, low compression will be found on that cylinder during an AFM compression test, along with a consistent valve train tick noise, SES light, DTC P0300 and engine misfires on the related cylinder.
Has GM fixed the lifter issue?
Unfortunately, the GM lifter problems are currently being handled on an “as-needed” basis, so owners will have to wait and see if problems manifest on their own vehicle. So, far GM has not issued any national recalls. Luckily, it seems that the lifters problem does have a fix that is working.
What is GM doing about lifter problems?
While GM has not issued a lifter recall, the automaker has implemented a policy called Component Coverage, which provides extended warranties for vehicle owners and lessees who have sent their vehicle in for repair at least two times as a result of valve train and lifter issues.
On some 2021 full-size truck and SUV models, General Motors has issued a service recall, GM Authority reports. Vehicles with a naturally aspirated 6.2-liter L87 V8 or a 5.3-liter L84 V8 gasoline engine might experience issues with the valve lifter lock pin spring.
What does a AFM delete kit do?
Install an AFM Disabler
An AFM Disabler is an electronic device that plugs into the OBD-II port, under the dashboard. It prevents the computer from switching over to four-cylinder mode. It’s a simple and effective way to turn off the AFM system and provides the added bonus of improving exhaust sound.
What causes engine lifters to fail?
Hydraulic lifters will fail if it doesn’t receive oil to dampen the cushion from the pushrod or tappet. In addition, solid lifters will corrode, and you may also see corrosion on the camshaft lobe. Excessive engine oil in the crankcase will cause bubbles or aeration, causing the oil to lose its lubricating properties.
What does a failing lifter sound like?
Instead of a knock or ping, a faulty hydraulic lifter will usually make a sound more reminiscent of a tapping sound. The tapping will be quick in rhythm and may occur when the vehicle is cold or hot, depending on what the problem with the hydraulic lifter is.
How do I cancel AFM?
Can you replace just one lifter?
No you do not have to replace all of the hydraulic valve lifters but I recommend that you do. You have to open up the engine just to get the single one out so might as well replace all of them while you’re at it.
Does lifter tick go away?
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.