AFM / DOD Delete

[clogan2]

Just drive in manual 9

Or, for a '16 model, use M5.

 

[MobileHomie]

This is all very helpful. Thank you.

Ballpark, what should an ECM tune cost from a reputable tuner?

Deleting the hardware... is this a "tear the engine down" type of mod? How expensive and complex?

Finally, what happens when the dual mode lifters fail?

OP, I have a 2017 Yukon Denali with 6.2L and an 8 speed.
I am going to answer your last question first. What happens when a lifter fails? Within moments the pushrod will bend. If the engine continues to run it will destroy the cam shaft very quickly putting metal shavings in the crank case requiring a complete tear down and rebuild of the engine IMHO.

In my opinion the tune or dongle disabler is a stop gap measure. I did install a Range dongle when I bought the rig with 32K miles on it and have no idea what a tune would cost.

At 62K miles a light tick made itself known of a morning, I believe this was the lifter failure, moments later the tick got louder, bent pushrod. I drove it two miles home and shut it off.

I made the decision to delete the AFM cam and lifters, I called them "tender bits", and a high performance engine needs a solid valvetrain.

Anyway I contacted a speed shop in the nearest city to me, Reno, trailered it there and had them do the deed. The list of parts is quite extensive including stage I BTR cam/lifters VLOM, and oil pump. They pulled the engine from the chassis for this job. Dyno graph says 352 HP at the back tires. The whole thing was about $6,200.

Come to think of it, the lifter failure was Feb 19 last year. It took till April to get it in the shop and I have been very happy with the results, sill puts a smile on my face a year later. MPG wise, it gets 19.5 with the cruise set at 87 mph, not bad for a full size SUV.

 

[Marky Dissod]

MpG wise, it gets 19.5 with the cruise set at 87MpH, not bad for a full size SUV.

19.5MpG, after deleting the DOD. What MpG did it get when it had DOD?

 

[MrMonte]

I had my AFM tuned out for 30K+ miles & still had an AFM lifter failure on my 2018 Yukon Denali. I have 6k miles on my AFM delete & went from 20 to 21+ mpg with mixed driving. My 50 mile round trip to work nets me 25-27mpg depending on how may lights I hit. The extra power thru the whole rpm range is a big plus. I did the AFM delete cam swap myself.

 

[MobileHomie]

19.5MpG, after deleting the DOD. What MpG did it get when it had DOD?

There was no noticeable difference. Bear in mind, I have a lead foot and like fast cars and guns.
My cite of 19.5 mpg is for a port to port trip to Reno and back, cruise set at 87 mph, 320 miles, no idle time or stop and go traffic.
One of the computer generated "trip meters" was set in January of 2022 and shows an overall mileage of 11,318, 15.4 mpg and average speed of 29 mph.

 

[Marky Dissod]

That's the other problem with V4 mode.
The amount of fuel V4 mode saves does not justify its existence, even before it fails.

Plus it can increase oil consumption, and make it happen sooner.

 

[jets]

16 Denali 6.2 8-Speed. I had a tune and AFM disabled recently. It went from 290HP/308TQ to 328HP/339TQ at the wheels. I had them tune it with a more aggressive throttle response and the truck runs so much better. In the future I plan to delete the lifters, install a bigger cam and headers while it's opened up. My shop said when I decide to do that it'll cost around $7500CAD/$5600 USD. Between this and the lowered Belltech springs/struts/magdelete it's a total transformation.