Pros/cons of tuning GM 5.3 with AFM?

[HawkeyeScott]

2008 Suburban 1500 with the 5.3L AFM flex fuel engine. Just under 130K. Used mostly for commuting in-town at about 35 mph, 10 miles each way. Some summer towing up some pretty hefty mountain inclines, pulling a 4250 lb. trailer and gear.

I've been kicking around the idea of shutting off the AFM. I don't mind the idea of it, but as the components wear, their chances of failing obviously increase. It seems like a fairly complex system and I know the failed lifter fix isn't cheap. That said, the system is functioning flawlessly and the truck uses virtually no oil.

I initially looked at just shutting down the AFM with one of the Range devices. Their simplicity is great. Now, I'm wondering if a custom tune via a place like Black Bear makes more sense. My goal would be to maintain as many MPGs as I can, maintain towing performance, and prevent the AFM-related failures I read about. Perhaps that can be done via a tune.

I plan on keeping the vehicle for years. I've maintained it, hopefully, to go 200K. The difference in cost between a tune and the Range device won't be much of a factor.

Any advice one way or another? My mind is wide open on this right now.

 

[dogememe]

do it! i like the idea of it doing it with a proper tune so your obd port is still usable but that's just me...

 

[gfh77665]

Originally Posted by HawkeyeScott

. I've maintained it, hopefully, to go 200K. The difference in cost between a tune and the Range device won't be much of a factor.

Any advice one way or another? My mind is wide open on this right now.


Want 200K? Kill the AFM. Actually you are looking at 300K with a dead AFM!

 

[Traction]

I had my AFM tuned out for $120. It runs much smoother, but it naturally hurt the fuel consumption a bit. If your towing that shouldn't be much of a factor.

 

[HawkeyeScott]

Traction - What kind of a reduction have you seen in MPG?

 

[4WD]

Does it have a display showing V4 vs V8 … my 2018 is almost never in V4 …

For mods I yield the balance of my time to Clinebarger …

 

[HawkeyeScott]

Yep, display shows V4 and V8. Guessing it's in V4 no more than 20% of the time.

 

[Bobaloo22]

I've got a 2015 Silverado, 5.3 and I tow a travel trailer. I got a Diablo tune and had a custom tune done by Diablew tune. It is a thousand times better than stock and Lew at Diablew knows his stuff. If you buy the tuner through him with the custom tune it is around $450 give or take. I love the power when I pull the trailer, dropped AFM and lost a little over a half a mile per gallon. Best thing I did to my truck!

 

[sprite1741]

The Hypertech 2000 will do it. It will also firm up your shifts and tune for different grades of fuel. You don't have to leave it plugged in like the Range and set up your engine the way you want it, and you can return it to stock if you need to. I got mine for $249. They are $288 on Amazon today.

 

[zrxkawboy]

I was in the same situation with my 07 Silverado. Ended up buying a used Diablo tuner and getting a tune from Diablew. He is knowledgeable and will answer any questions. I got an 87 tune, so the difference isn't drastic, but it does run better, gets slightly better mpg, and definitely shifts better.

 

[spasm3]

Does tuning out AFM stop lifter and lifter or valvetrain issues?

 

[Snagglefoot]

Originally Posted by Bobaloo22
I've got a 2015 Silverado, 5.3 and I tow a travel trailer. I got a Diablo tune and had a custom tune done by Diablew tune. It is a thousand times better than stock and Lew at Diablew knows his stuff. If you buy the tuner through him with the custom tune it is around $450 give or take. I love the power when I pull the trailer, dropped AFM and lost a little over a half a mile per gallon. Best thing I did to my truck!


Not to be a jerk but only to keep the others informed, the AFM was totally redesigned in 2014. Your choice to delete it, but I understand the 2014 and up versions are quite reliable. I see you were seeking the Tune more than anything.

 

[clinebarger]

Originally Posted by spasm3
Does tuning out AFM stop lifter and lifter or valvetrain issues?


Unfortunately, It doesn't. L92 engines made in 2006 for the then "all-new" 2007 Escalade were equipped with AFM hardware but wasn't enabled in the calibration.......Lifters would fail/collapse even with the AFM never being operational.

Disabling the AFM helps with oil consumption more than anything.....Granted the engine has a deflector shield over the oil pressure relief valve. (Engines built before October 2010 did not have a deflector from the factory)

There is NO proof that disabling the AFM will prevent a collapsed lifter, Lifter roller failures are a separate issue altogether that effects engines without AFM hardware as well.