AFM Problems ?
Thread Starter
Pro
Joined: Jan 2014
Posts: 566
Likes: 163
From: Earleton Fl
AFM Problems ?
At a recent Corvette Club meeting one of the members gave us a lecture on the failures of GM's AFM-Active Fuel Management system, along with similar problems with other manufacturers systems. He claimed that the AFM system led to premature cam lobe failure, bent push rods, broken value springs, and bent valves.
I follow this site on a daily basis, and have searched for any posting of such problems, and can find none. My own experience with AFM has been good. I am wondering is there is any truth to his rant? Comments please...
I follow this site on a daily basis, and have searched for any posting of such problems, and can find none. My own experience with AFM has been good. I am wondering is there is any truth to his rant? Comments please...
Burning Brakes
Joined: Jun 2014
Posts: 981
Likes: 157
Since the AFM functions by disabling the valve lifter, I don't see any way that would put any extra stress on the cam lobes, pushrods, valves, or springs. If anything, those components are getting a rest when the AFM kicks in. Unless there's a failure mode that involves getting excessive valve lift, I'd say there's no reason to worry.
Dazed Confused & Verklemp
Joined: May 2008
Posts: 1,398
Likes: 109
From: Naples, FL & Clear Lake, IA
My son had an AFM lifter failure in his 2009 G8 GT at 29K and a week before the 5 yr warranty ran out. GM replaced all of his lifters under warranty. He had 2 ECM's, the original, and a Vector tuned ECM that was his normal ECM. The Vector tune deleted the AFM function, so the AFM lifters were operating 100% of the time.
Since I have 2 G8's, one with a similar setup and the other with a different cam which removed all the AFM, I can say that our Vettes AFM is much smoother in transition, vs the G8 AFM which was noticeable every time it turned on and off. At non-highway speeds I don't even notice when it switches when in E mode.
I don't think we will have issues with this, though also realize that few 2014 - 15 owners have exceeded 30K. That's why you have your 100K - 5 yr warranty. Personally, I am much more concerned with the oil in the intake.
Since I have 2 G8's, one with a similar setup and the other with a different cam which removed all the AFM, I can say that our Vettes AFM is much smoother in transition, vs the G8 AFM which was noticeable every time it turned on and off. At non-highway speeds I don't even notice when it switches when in E mode.
I don't think we will have issues with this, though also realize that few 2014 - 15 owners have exceeded 30K. That's why you have your 100K - 5 yr warranty. Personally, I am much more concerned with the oil in the intake.
Thread Starter
Pro
Joined: Jan 2014
Posts: 566
Likes: 163
From: Earleton Fl
Le Mans Master
Joined: Apr 2001
Posts: 5,473
Likes: 717
From: Black Forest CO
I can't speak to any problems with LT1 AFM but can with the AFM in GM trucks. I had a 6.0 Truck with AFM and it had lots of AFM related problems. They tore the engine down twice in 25k miles to replace the valve train components due to problems directly related to AFM. I have the AFM disabled in my 12 Avalanche and no problems so far.
Burning Brakes
Joined: Jun 2014
Posts: 981
Likes: 157
I can't speak to any problems with LT1 AFM but can with the AFM in GM trucks. I had a 6.0 Truck with AFM and it had lots of AFM related problems. They tore the engine down twice in 25k miles to replace the valve train components due to problems directly related to AFM. I have the AFM disabled in my 12 Avalanche and no problems so far.
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