Rattle

TX14Z71 · December 31, 2014

So I've been hearing a rattle that sounds like it's coming from underneath/driver side. I looked and found the exhaust was fine, but the fuel cell undershield and the fuel purge valve assembly (may not be correct names) are very flimsy and cause this rattling noise. Noise appears more during a cold start. I've attached a pic of both rattling things.

GMCustomerService · December 31, 2014

Hello TX15Z71,

I see you're reaching out regarding the rattling noise in your 2015 Silverado. Although I'm not trained as a technician, please feel free to send a PM if you decide to take it in to get checked out. I'd be happy to reach out on your behalf and research this further.

Sincerely,

Eddie A.

GM Customer Care

TX14Z71 · January 1, 2015

Does anyone know of a fix?

austingta · January 1, 2015

I do. Take it to the dealer.

20L8TSierra24 · January 1, 2015

Big zip ties

jeffsig · January 1, 2015

Can you make a video of the sound? These trucks have two fuel pumps and the high pressure one under the hood makes a rattling type sound during cold startup. If this is indeed your sound, it's normal. I thought the noise was the heat shield initially.

TX14Z71 · January 1, 2015

I'll try to make a video today. I appreciate your help.

jeffsig · January 1, 2015

Does this sound like your startup noise?

TX14Z71 · January 2, 2015

It's hard to tell. I went outside and tried to record it, but it didn't make the noise. When we had the truck in the lift we started feeling around and those two things I put arrows on were making the same noise.

mafd2 · January 3, 2015

Noise is coming from the exhaust flapper valve. Most people just tie them open. There's a thread somewhere on the forum about it.

mafd2 · January 3, 2015

Here are some threads.

http://www.gm-trucks.com/forums/topic/153020-exhaust-adaptive-valve/

http://www.gm-trucks.com/forums/topic/164064-exhaust-valve/

thewhitestallion · January 4, 2015

in the picture you posed the object that your finger is touching in the charcoal canister just FYI.

TX14Z71 · January 4, 2015

in the picture you posed the object that your finger is touching in the charcoal canister just FYI.

Not sure I understand what you're saying. Please explain.

mafd2 · January 4, 2015

Not sure I understand what you're saying. Please explain.

What's there to explain??? The object you are pointing at in the pic is the charcoal canister FYI (for you information). Regardless, that's not where your sound is coming from and it's more of a squeak than a rattle. As I said, it's from the exhaust valve and none of the pics you have arrows pointing too.

TX14Z71 · January 4, 2015

in the picture you posed the object that your finger is touching in the charcoal canister just FYI.

I guess I didn't understand because you don't write very well, but I dumbed myself down 80% and figured out that when you wrote "posed" you meant to write "posted", and when you wrote "in" you meant to write "is". Now it all makes sense.