2017 Denali fluttering when accelerating. VIDEO

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denali17gmc

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Thanks everyone for your input/ideas!
So i went and did that bolt "hack" on the valve and it didn't really seen to do anything about the noise I'm hearing...
This is after having the entire exhaust swapped out by the dealer a few weeks ago. They said it was the valve making the noise and this was normal for these trucks, although I've test driven 3 other 2017 denalis and couldn't replicate the sound.
I have a service appointment at a different dealer this Wednesday, not too optimistic at this point but I'll keep you all posted.
 

thavngr98

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Please keep me posted on what they say.

I pick my truck back up this morning. For mine they found 2 exhaust leaks one on clamp weld at Cat and one on the hanger weld of the muffler. They had to order me a whole new exhaust system. Hope this helps...
 
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denali17gmc

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I pick my truck back up this morning. For mine they found 2 exhaust leaks one on clamp weld at Cat and one on the hanger weld of the muffler. They had to order me a whole new exhaust system. Hope this helps...

Took mine to a different service center this morning. They didn't want to deal with it... claimed I had to take it back to the original servicing dealer since they already started to look at the issue. BS...

So your issue all gone then thavngr98?
 

thavngr98

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Took mine to a different service center this morning. They didn't want to deal with it... claimed I had to take it back to the original servicing dealer since they already started to look at the issue. BS...

So your issue all gone then thavngr98?

Not yet they had to order the exhaust system. Said it would be in next week. Ill keep you updated...
 

DenaliDrivinDad

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Mine does this, and the range at which it rattles has grown. I also tested the flapper valve early on with no improvement. Checkout 27 seconds in this video.




Shortly after this, the dealership claims they just replaced the VLOM, the fuel lines including the fuel feed pipe mentioned in PIP5395A, and the high pressure fuel pump. They also claim to have checked the pushrods. The noise is still there for me. I'm at 9200 miles now.

My Denali is one of the noisiest vehicles I've owned.
 
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denali17gmc

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Mine was at the dealer all last week, they replaced a belt that was showing uneven wear... it did not solve the problem.

Took the truck back in on Tuesday but still haven't heard anything from them.

Mine makes this "clicking"/"fast flapping" kind of noise at low speeds and at highways speeds it can turn into a squeaking kind of whistle. The pitch it can hit is really bothersome. I know they think I may be exaggerating but there is no way this is normal...
 
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denali17gmc

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This is so strange to me... can't believe they consider this normal. It's really is extremely annoying especially because I spend much of my car travel time during the week returning work phone calls. I can hear the sound fluctuating as I adjust the gas pedal. Frustrating.

I believe you are hearing characteristic noise that comes in with V4 engine operation. The valve in the exhaust is intended to minimize it. I don't believe there is anything that will eliminate it in the long term. I have seen several exhaust systems replaced for this but the noise comes back.
 
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denali17gmc

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Mine does this, and the range at which it rattles has grown. I also tested the flapper valve early on with no improvement. Checkout 27 seconds in this video.




Shortly after this, the dealership claims they just replaced the VLOM, the fuel lines including the fuel feed pipe mentioned in PIP5395A, and the high pressure fuel pump. They also claim to have checked the pushrods. The noise is still there for me. I'm at 9200 miles now.

My Denali is one of the noisiest vehicles I've owned.

I'm regretting my purchase. Some may say it's a minimal sound I'm getting but I expect a reasonably quiet ride from a vehicle with this price tag.
 

jeffbco

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I'm regretting my purchase. Some may say it's a minimal sound I'm getting but I expect a reasonably quiet ride from a vehicle with this price tag.
Does the noise change/go away if you turn off AFM. You can effectively do this by selecting "L" in the transmission, advance the gear using the toggle to 7 on the gear shift lever and you'll remain in V8 mode until you shift to 8 - car will shift normally through gears 1 - 7 set this way. At least you'll be able to tell if it's a V4/V8 issue. Good luck.
 

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