Exhaust leak? Rattle? Normal?

OnTheReel · September 27, 2016

Hi, I'm dealing with an annoying noise in my 2016 Sierra. I noticed it a few days after purchase. I'm 1500 miles in and it's really starting to get on my nerves. Before bringing it in for service (need recall done anyway), I'm hoping to hear from anyone else as to if this is a normal sound, or if someone has had the problem fixed and what was done...

Basically at part throttle at highway speeds there's this almost squeaky sound that seems to come from the driver's footwell. It gets louder as the throttle is pushed down, but then the other engine noise sort of masks it. It does it in V4 and V8 although I think V4 makes it more obnoxious. I was thinking either something is loose or it's an exhaust leak, but not too sure. All I know is I have to have the radio pretty loud to drown it out, and it really is irritating.

I recorded a video today, hopefully you can spot the sound as I modulate the throttle up and down. Any thoughts?

ShamrockShooter · September 28, 2016

It is probably the flapper valve after the muffler. There are a bunch of posts about it. Mine makes the same noise. Clamp it open with a hose Clamp and see if the noise goes away. You will hear drone and chopper in v4 with it clamped open though.

MOhunter92 · October 10, 2016

Mine does this. Extremely annoying. I am telling them to check for the sound now, I am starting to think it's an exhaust leak up front. It is not the flapper valve noise, that is located in the back of the exhaust all the way at the rear and makes more a squeak sound, I had that replaced on my 15 and I have a 16 now

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CounterMeasure · October 10, 2016

Yes, I have that noise too. Get it crusing at about 1500rpms and V4 and apply a little gas and it rattles like that. It does it when idle when cold or humid too. Very annoying. I am convinced its from the front cat on the driver's side. Dealerships haven't been able to find it and fix it, so I gave up.

2016 Sierra Owner · October 10, 2016

Being in the area you have in the video (I can't play it at work) and you have a 4x4. People have been complaining in the past that the 4WD selector switch makes a whining noise. This could be the problem as well.

scottl1346 · October 11, 2016

http://www.gm-trucks.com/forums/topic/161230-v4-to-v8-mode-squeak/

Kbuell21 · February 22, 2017

Did anyone ever figure this out, it's driving me crazy?

congden · February 22, 2017

Mines at the dealer now for what i would call the exact same noise, drives me insane as well and even with an aftermarket exhaust i can still hear it and makes the truck sound like a piece of crap with a manifold leak.

BigBadSierra · February 22, 2017

I wonder if a chunk of ceramic broke off in the catalytic converter. I had that happen in a car once but it just stirred and rattles like that.

You have to remove it and give a shake to know for sure though.

Kbuell21 · February 24, 2017

Got my truck back yesterday they said it was my aftermarket Gibson headers making that same noise as onthereals video. Is yours stock?

Dmendoza · June 12, 2017

Anyone find a fix for the noise in the video?

Hey_Fam · June 12, 2017

still happens to me.

2strokesmoke · June 13, 2017

still happens to me.

Fuel pressure check valve line, located at rear of engine closer to the right side.

This will make a rattling noise when check valve is defective. Check valve is located inside this short fuel line piece.

Hope this helps you find your issue, not gonna claim that this is your problem though but a possibility!

Here you go for a read

http://sandyblogs.com/techlink/?s=Check+valve&search=Search

Good luck

Edited June 13, 2017 by 2strokesmoke

2strokesmoke · June 13, 2017

Did anyone ever figure this out, it's driving me crazy?

Here you go possibly your issue.....http://sandyblogs.com/techlink/?s=Check+valve&search=Search

Good luck

Dmendoza · June 13, 2017

Fuel pressure check valve line, located at rear of engine closer to the right side.

This will make a rattling noise when check valve is defective. Check valve is located inside this short fuel line piece.

Hope this helps you find your issue, not gonna claim that this is your problem though but a possibility!

Here you go for a read

http://sandyblogs.com/techlink/?s=Check+valve&search=Search

Good luck

There's a service bulletin out for the link you copied. I had it done a few weeks ago and didn't fix anything.