I have done many searches and ready many threads and watched the youtube videos here but none of them really helped me.
My 15 has developed an odd sound on startup. Cold startup, cold as in overnight or sat most of the day.
I start it. Everything is normal for about 10 seconds, then I start to hear this sound coming from it seems the passenger side. it lasts for only about 20 -30 seconds and is gone until the truck sits again for hours. It reminds me of a leaky air compressor or very small exhaust leak. It has that sort of airy ticking sound.
I am puzzled because I would expect if it was exhaust leak it would not go away so easily. So I was thinking what could it possibly be? Turbo? wastegate? But I would think there are sensors there and I would expect some sort of code if something was failing.

I just hate to take it to the dealer even though I have warranty because they are going to have to keep it for a couple days probably.
Any thoughts on what I could check>?

 

It's just the turbo wastegates rattling while it warms up. Mine's done it from day 1. 3 years and 94k later, still does it, but I'm used to it.

I'm sure many other people will also comment saying it's normal. If you're really worried, take a sound clip and post it for everyone to hear.

 

Here is a short video I made this morning. The ticking type sound is much clearer in person than in the recording but you can hear that it goes away.

 

Hmm. That does sound a bit like mine, but yours seems much faster... I'd have to listen again to a cold start on my truck because I don't pay attention to it anymore...

 

Listen under the hood and see if it's coming from the timing cover.

 

I did notice that it is much louder and clearer to hear on the passenger side wheel well than the driver side.