Active Fuel Management Issues / Question

ElJefeBlanco · November 25, 2017

I have a 2016 Crew Cab Silverado 4x4 that I bought new last summer. I have noticed that recently when the active fuel management switches from 4 to 8 cylinders that there is a loud (loud enough to hear it with the windows up, A/C and radio on) squeak like noise that comes from the truck. It makes this noise every time it switches from 4 to 8, no matter what the speed.

I don't remember it doing this until recently. I've googled active fuel management noise, active fuel management squeak and tons on other combinations, but haven't gotten any results.

I wanted to check on here and see what you guys thought before looking like a dumb ass and taking it back to the dealership.

Largely Unknown · November 25, 2017

I have the exact same issue, and plan to take it in to be checked in the near future. Mine has 1500 miles. Lots of topics here on the forum, mostly dealing with removing the valve, bolting the valve open, disabling AFM - etc. Personally, I'm going to give them a chance to fix it first. Eventually, I plan to get the GM Borla exhaust upgrade, which has a flapper valve (hopefully a better quality one), but at $1300 it could be a little while. I've gone to the dealer a couple of times for minor issues (road force balance, and a software update on the backup camera). They didn't give me any grief. Maybe I lucked out - my dealer is privately owned, not corporate, and the techs have been there forever. The folks there seem happy and willing to help. Again, pure luck in todays world.

Sierra706 · November 25, 2017

Bring it to the dealership and they will install a new muffler with a redesigned flapper valve under warranty.

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newdude · November 25, 2017

1 hour ago, Bushleaguechew said:

Bring it to the dealership and they will install a new muffler with a redesigned flapper valve under warranty.

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What he said

15 Z71 · November 25, 2017

9 hours ago, Bushleaguechew said:

Bring it to the dealership and they will install a new muffler with a redesigned flapper valve under warranty.

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Mine has been doing this also,took it dealer and they said can't duplicate it. So there for they don't want to do anything.It drives me crazy.

Sierra706 · November 27, 2017

Mine has been doing this also,took it dealer and they said can't duplicate it. So there for they don't want to do anything.It drives me crazy.

Someone on here might have the TSB #. Bring that to the dealer

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vinemann12 · November 27, 2017

The Adaptive Valve (Flapper) started squeeking at 800 miles on my 2016 RCSB..

Brought into dealer, took mechanic for a ride and was easily noticed, once exhaust really warmed up..

There is a TSB, but not sure what number, but dealer replaced with new (full) exhaust system..

Now with 8500 miles,, still quiet..

Photo is of new valve after installation..

Cheers----K

ElJefeBlanco · November 28, 2017

Thanks for all the input. I made an appointment for tomorrow morning. I'll let you know what they say.

ElJefeBlanco · November 28, 2017

On 11/25/2017 at 5:51 PM, 15 Z71 said:

Mine has been doing this also,took it dealer and they said can't duplicate it. So there for they don't want to do anything.It drives me crazy.

I'm worried that they'll say the same thing to me. It'll be easy to overcome if one of them will hop in and take a ride with me.

I don't understand how they can say they couldn't duplicate it, I can't get mine to stop doing it.

ElJefeBlanco · November 29, 2017

Well, I took my truck to the dealership this morning. It went a lot smoother than I had anticipated.

They had to order a complete new exhaust and I have to go back in 3 days to have it installed.

I plan on replacing the exhaust with an aftermarket one anyway, but I'm not sure when I'll get around to doing it.

I'll update later if there are any issues or if anyone needs any information regarding a TSB number or any information that may be on my paperwork when they finish repairs.

n1ghtsh1ft · November 30, 2017

I took my '17 Sierra in for the same thing today. After doing a bit of digging online, I referenced PIT5404D (Dated June 16, 2017) and the techs were able to reproduce the squeak and verify that PIT5404D was the correct bulletin. I'm in Canada, it will take a week or two to get whatever parts necessary to fix it.

ejdziurka · November 30, 2017

On 11/27/2017 at 11:13 PM, ElJefeBlanco said:

I'm worried that they'll say the same thing to me. It'll be easy to overcome if one of them will hop in and take a ride with me.

I don't understand how they can say they couldn't duplicate it, I can't get mine to stop doing it.

I swear I get the deaf, blind technician every time I take my truck in for something.

KARNUT · November 30, 2017

Well, I took my truck to the dealership this morning. It went a lot smoother than I had anticipated.
They had to order a complete new exhaust and I have to go back in 3 days to have it installed.

I plan on replacing the exhaust with an aftermarket one anyway, but I'm not sure when I'll get around to doing it.

I'll update later if there are any issues or if anyone needs any information regarding a TSB number or any information that may be on my paperwork when they finish repairs.

GM has a factory performance exhaust upgrade, maybe you could get them to do that instead of stock replacement.

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