Weird Engine noise

Okay so recently I have had a weird engine noise or what sounds like an engine noise start coming from my truck. It sounds like a "woodpecker". Thats the closest comparison I can come up with. It does it after the truck has sat for a night and only does it for maybe a 1/4 mile not even. Today it made the noise and made it loudly for maybe 500ft, then since I had to stop at a red light it quieted up as I accelerated for the second time. Now this noise does not do it all the time either.

If you watch the video closely you will here the sound within the first couple seconds before I start to talk, then you kinda hear it after I start to drive again from waiting at the light.

Let me know your opinions. Thanks

Video Link: https://www.youtube.com/watch?v=3dwMYrKyyRA

 

Maybe a loose fan shroud, and its coming in slight contact with the fan sometimes?

 

I watched your YouTube, I have the same noise. It started after the outside temperature dropped. Dealer can't find out what the problem is. I taped the fuse box cover down and it seems to have stopped. The cover is very loose and the dealer said there was nothing therapy could do but leave the tape on.

 

Humm... I shall look into that. I took my truck to the dealer recently and talked with a mechanic. Apparently i have piston slap. The dealer said it is normal and nothing to worry about. I then called a mechanic and he said its not normal but its not worth taking the entire engine apart either unless it gets extremely loud, or I start burning oil, or something noticeably goes wrong.

 

Let me know if it works for you. Since I taped my box lid down securely, I have not heard the noise. I'm curious to know why they said you have piston slap.

 

Thanks for the replies, and my apologies for being gone for so long. As the winter months start to come back around this year I will be listening to my truck again for the same noise. Attached is a video from last year, with the sound a tad bit quieter however it lasts for more time. Take a listen and let me know if the sound is still close or the same to what you had. Thanks again.

https://www.youtube.com/watch?v=aM3DSBX6FJo