I have a 2015 GMC Sierra with only 4000 miles on it and it makes a rattling noise when it starts then when it hits 210 on temperature it stops the noise what could be the issue

Is that i big issue that i need to get fixed immediately or will it eventually work its way into place and stop.

I just looked at the heat shield and that is the noise but how do i go about fixing it so that it doesn't rattle against the part that its affixed to.

That you will have to use your imagination on, short on trying to work with rusted bolts, doubt that you can tighten it up, or see where exactly where it rattles against an slightly bend it away.

Oh, the heat shield is no big deal to get fixed as long as it is not causing any problems other than noise. No immediate fix is necessary.

Thank you I will see if what i did work and if it was the actual heat shield in the morning that will be the moment of truth. Thank you for your advice it is greatly appreciated.

Your welcome.

I tried that out and it still made that awful noise this morning until it hit the 210 mark on the engine thermometer. What else could it be i looked at the heat shield and tried to see where it was touching and I couldn't find it. I tried this morning to see if it was the spark plugs by putting it in drive and pressing the gas and the brake at the same time and it didn't make the noise.

What you are describing is weird. Rattling stops when engine reaches operating temperature. Do you know where the sound is the loudest, the area the noise is coming from?

It sounds like its under my feet when I'm in the truck not necessarily in the engine but underneath. I can hear it from both wheel wells but it definitely is underneath or at the lower part of the engine. Its a weird noise and there seems to be nothing wrong with the truck operating wise other than that noise. It sounds close to the oil pan to be honest.

I have started the truck several times since this morning to see if the noise would start back up but it doesn't its very quite.

Well then it has to be in the exhaust somewhere, maybe take it to a shop for them to have a look? I'd tell you more but I just can't hear the sound from here.lol

I was just told by another person that it could be the torque converter or lifter problem.

Well that is a big jump. You can tell the difference between the two. Lifters are a tick, tick, tick, The torque converter if it was loose you would feel a violent shake at your feet. This thing is a 2015 with only 4000 miles on it, what does the dealer say on this?

Could be just the common driveline slip yolk clunk. Does this still happen with 2015s? When people take it to dealer as a concern, they usually say this is normal.