New 4.3 and AFM question

[wilnis]

Hi-got a 17 silverado with 4.3 and AFM. It is the new 4.3 engine so no experience to speak of on internet, and does have the AFM about which I have questions. There is a device from Range Technology that goes into the OBDII that will make the AFM not work which I find many people with the 5.3 V8 love and feel it helps prevent the problems with long term use of the AFM but there is nothing I can find about this with the new 4.3. I called the dealer and they said the new engine will "probably" not have this problem and I'm not feeling relived.
My questions are does anyone know about this device in the 4.3 v6 engine, does the new engine have some technological difference that will prevent the AFM from causing cylinder problems, and would it cause any problems just to use the Range Technology device anyway to try and prevent any future issues. I have 8500 miles, no issues and the 4-6 shift in cylinders is seamless on my truck whereas others say they can feel the difference in the older vehicles.
Thanks in advance for any information, websites, or recommendations.
Bill

 

[The motor guy]

I remember this on the dodges where they constantly de activated the same cylinders instead of alternating 4 cylinders, so once you got 100,000 miles the compression was off and their was a skip.

 

[440Magnum]

Originally Posted By: motor_oil_madman
I remember this on the dodges where they constantly de activated the same cylinders instead of alternating 4 cylinders, so once you got 100,000 miles the compression was off and their was a skip.


Absolutely false- the part about "compression off and a skip" anyway.

Yes, the same 4 cylinders are always deactivated, because only 4 cylinders are equipped with the hardware needed to deacticvate! But the engines show NO uneven wear as a result at ANY mileage. The early GM versions had some issues with rings sticking because of prolonged deactivation. A software update (more than TEN YEARS AGO now!) fixed that. The Dodge version, from the outset, would turn on the cylinders at intervals to keep them up to temperature and prevent oil accumulation in them.

There was a ton of internet hand-wringing and proclamations of "4 cylinders will be dead before 100k miles" back when this came out in the early 2000s... it was all proven completely wrong. Is MDS/AFM perfect? Does it NEVER have a problem? No, nothing mechanical is perfect. But the take-away is that MDS/AFM doesn't affect engine life or failure rate in any statistically significant way whatsoever, at least on the Chrysler and GM v8s. There's no fundamental reason to assume that the v6s will fare any differently.

 

[A_Harman]

440 Magnum pretty much summed it up.
The deactivating lifter in the 4.3 is the same as it is in the 5.3, but there are only 4 of them in the engine, instead of 8. It's mature technology. In the V6, when the 2 cylinders deactivate, you have a 2.9L V4. In the V8, when 4 cylinders deactivate, you have a 2.65L V4. So basically the V6 has 10% more displacement in deac mode than the V8 does, which means it should be able to be in deac mode more of the time.

 

[GenesisGuy70]

I'm all for VVT and DVVT and start/stop and all this new stuff but something about turning off cylinders mid drive just gives me the creeps. I don't think I'll be purchasing a car with that.

I know I know, who am I to speculate or bash it, I'm no engineer, but the whole concept just makes me uneasy.

Though I know that's unjustifiable. Sue me!

 

[NYEngineer]

My brother and I both have trucks with 5.3s. His 07 Tahoe and my 09 Suburban. His engine ate a camshaft when one of the deactivating lifters failed. He installed a brand new engine that we replaced the four lifters with standard ones and the top plate that blocks those oil passages. He had the cylinder deactivation tuned out of the computer while the engine was out.
I bought the Range Technologies thing for now.
Both trucks run great and I actually think I'm getting better mileage with it turned off. Since I travel in my truck a lot, I'm considering getting a fresh engine in a year or so and doing the same as my brother. But so far, at 130,000 miles, it still runs great.
I think the Range part does the exact same job on the V sixes as it does on the eights.

 

[01rangerxl]

Originally Posted By: NYEngineer
My brother and I both have trucks with 5.3s. His 07 Tahoe and my 09 Suburban. His engine ate a camshaft when one of the deactivating lifters failed. He installed a brand new engine that we replaced the four lifters with standard ones and the top plate that blocks those oil passages. He had the cylinder deactivation tuned out of the computer while the engine was out.
I bought the Range Technologies thing for now.
Both trucks run great and I actually think I'm getting better mileage with it turned off. Since I travel in my truck a lot, I'm considering getting a fresh engine in a year or so and doing the same as my brother. But so far, at 130,000 miles, it still runs great.
I think the Range part does the exact same job on the V sixes as it does on the eights.


On Gen IV engines I am still a proponent of disabling, and if there is a failure, removing AFM. There IS a pattern of issues there, though many also live long lives. GM did miss the mark early on.

But, I will also say, I think they have learned from it. I have yet to see a Gen V with issues like the Gen IVs had. So far the Gen V (Ecotec) seems to be very reliable.

 

[AZjeff]

I just got a leftover '16 Silverado a month ago with the 4.3 and have the same concerns/questions about the AFM and DI. This motor came out in '14 so it's not brand new tech. I plan to run 5K OCIs with synthetic, currently have Pennzoil PP on hand, until warranty is up, then see what's what. It doesn't go to V4 much but when it goes in and out it's seamless - you'd never know without the indicator. This tank of mixed driving is showing 24.8 mpg.

 

[Tomioka]

I had 100mi of seat time in a '16 GMC Sierra C1500 5.3L reg cab long bed (u-haul rental) and without the V4-V8 readout I couldn't tell if the engine was in 4 cyl or 8 cyl mode. I almost netted 17MPG mixed driving, compared to 15.5MPG in my 02 Silverado. In light cruising either on the freeway or in a residential area the engine goes into 4cyl mode. I'm surprised that it will be cruising in 4cyl mode going 30mph at light throttle input. I'm keeping an eye on GM forums if it becomes a long term issue which will affect my decision when buying a used truck. I'm dead set on getting a GMC Sierra when the used truck market looks good.