Active Fuel Management kills another lifter

Dock Rocker · April 11, 2016

I turned 100,000 on my 2014 Sierra the other day. Literally the next day I heard a little chirp. I figured it was an idler pulley so I took it to a friend's shop to get the pulley fixed as well as new belts and plugs. The next thing I get is a call from John saying it's not an idler pulley but it's a lifter. The noise had gotten progressively louder. Sure enough with a little Google foo I find out this is a real problem with the LS motors with active fuel management.

I am having them replace the filter screen at the sending unit as well as sort out the lifter issue. Thankfully the dealer is going to pick up 90% of the cost under warranty even though I was over 100,000 miles. I already have a tune from Black Bear waiting to completely disable the AFM. I hope this will allow the lifters to last longer than 100,000 miles.

Anyone with AFM if I were you I would consider tuning it out. Apparently it's really tough on the lifters.

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newdude · April 11, 2016

2014 are LT engines (Generation 5 small block) not LS engines (Generation 3 and 4). Failures are not overly common but they are present. GM has seen some potential for oil aeration on the new engines as a cause for AFM lifter failure.

txab · April 11, 2016

Since it's out of warranty from here on, I would have completely removed AFM junk and replaced with non-AFM parts and then tuned

Dock Rocker · April 11, 2016

Since it's out of warranty from here on, I would have completely removed AFM junk and replaced with non-AFM parts and then tuned

I gave that a try. The dealer is going to pay 90% of the bill is nce they are picking up most of the tab I am going to have to go back stock.

I tried to get them to lose the AFM parts and let me handle the tune but they wouldn't let me.

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Rkaroll953 · April 12, 2016

i have read a lot about the lifter issue when in v4 even had a friend who has had to replace a few. bought the Range device at 5k miles and not looking back. dont notice a difference in mileage

GMC207 · April 13, 2016

i have read a lot about the lifter issue when in v4 even had a friend who has had to replace a few. bought the Range device at 5k miles and not looking back. dont notice a difference in mileage

Thinking of getting this device. Only thing holding me back is I've read a few people saying you have to unplug and replay back in every startup? Is that true or?

Rkaroll953 · April 13, 2016

Thinking of getting this device. Only thing holding me back is I've read a few people saying you have to unplug and replay back in every startup? Is that true or?

its worth getting. it completely shuts off the v4 mode and if i unplug it goes right back to using v4. but yea only drawback is if you let the truck sit for 4 days the battery will be dead enough not to turn the truck over. i have gone 4 days in the cold and it barely started. 2-3 days it starts but aint happy. basically if i know im going to let it sit for more than a weekend i will unplug it. its really not that big of a deal.

beetle · April 13, 2016

I've considered disabling only the AFM with a tune but I'm not clear on who, where or what it would cost. Any suggestions? Not interested in any other tuning changes.

Rkaroll953 · April 13, 2016

I've considered disabling only the AFM with a tune but I'm not clear on who, where or what it would cost. Any suggestions? Not interested in any other tuning changes.

look into a Range AFM disabler. Takes v4 away and doesn't flash the truck so your warranty is secure.

blwright · April 13, 2016

I've considered disabling only the AFM with a tune but I'm not clear on who, where or what it would cost. Any suggestions? Not interested in any other tuning changes.

Find a tuner with HPTuners and purchase a credit. It's a lot cheaper than a handheld.

Rock1500 · April 13, 2016

What is the lifter and how much does it cost to replace?

If this is that serious of an issue I might do the same. I'm always doing city driving so my mileage can't get any worse.

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Hunter11 · April 13, 2016

Thinking of getting this device. Only thing holding me back is I've read a few people saying you have to unplug and replay back in every startup? Is that true or?

I have been looking at getting a Range AFM Disabler for my wife's truck since she hates the constant in and out of v4. She likes driving it in M5 but just can't remember every time to do it. I to would like to make sure before I order one that it does not have to be re-seated after each time the truck is turned off. I can't imagine having to do that as it would be a real PITA and she will not go for that. Not going to tune it and lose the warranty at this point.

Rkaroll953 · April 14, 2016

it is simple you just plug it into the obd2 port and forget it. only thing is if you are not going to drive the truck for 3-4 days i could drain the battery enough where it wont start or barely start. only had it happen to me once after 4 days in 10-20 degrees. it is set it and forget it until you bring it to the dealer you want to take it out. Its really worth having im a big fan. and it has a cool led light on it to illuminate the floorboard.

I have been looking at getting a Range AFM Disabler for my wife's truck since she hates the constant in and out of v4. She likes driving it in M5 but just can't remember every time to do it. I to would like to make sure before I order one that it does not have to be re-seated after each time the truck is turned off. I can't imagine having to do that as it would be a real PITA and she will not go for that. Not going to tune it and lose the warranty at this point.

TxTruckMan · April 15, 2016

I turned 100,000 on my 2014 Sierra the other day. Literally the next day I heard a little chirp. I figured it was an idler pulley so I took it to a friend's shop to get the pulley fixed as well as new belts and plugs. The next thing I get is a call from John saying it's not an idler pulley but it's a lifter. The noise had gotten progressively louder. Sure enough with a little Google foo I find out this is a real problem with the LS motors with active fuel management.

I am having them replace the filter screen at the sending unit as well as sort out the lifter issue. Thankfully the dealer is going to pick up 90% of the cost under warranty even though I was over 100,000 miles. I already have a tune from Black Bear waiting to completely disable the AFM. I hope this will allow the lifters to last longer than 100,000 miles.

Anyone with AFM if I were you I would consider tuning it out. Apparently it's really tough on the lifters.

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Like another poster said, this isn't an LS engine, so your Google search is meaningless.

How do you know AFM caused your problem? What cylinder was the lifter failure on?

And what filter screen and sending unit are you referring to? The fuel pump?

TJay74 · April 16, 2016

The minimum cost to turn off AFM using HP Tuners is $100, and that's if the shop didn't charge anything for their time, that's purely the charge for the 2 tuning credits ($50 per credit) needed to license the ECM/TCM.