After my truck sits a day or so it make a very loud noise on the initial startup, after that it doesn't make the noise. It sounds like it comes from the passenger side close to the firewall. It has made the noise sice I've had the truck but has been getting louder. I've looked under the hood and haven't found anything loose or see anything obvious. Anyone else experience this?

 

Need more info, your post is rather vague. Might be the turbo? IDK. We don't even know the year or model of your truck

 

Is your A/c on when you start?? Mine somtimes makes a noise when I start with the ac on or even turn it on right after start up. And it does sound like it's on the passenger side

 

If you haven't tried this... Turn off ALL of your accessories then try starting it... Have someone else start it while you have the hood up and are listening up front.. What works great if its a metal sound is a long screw driver with the tip on the suspect part and the handle up to your ear (don't laugh it works).. If your unable to detect the problem take it in and get them to replicate it.. BUT you say you only hear it after its parked for a day, you will need to leave the truck with them for them to hear it.. Good luck on your search..

 

My truck is a 2010 3500 dually with the 6.7 engine. The noise sounds almost like something is grinding and happens right as the engine fires and only lasts for a second. It only happens on the first start of the day and after that no more noise at startup. I apologize for the vauge description, it is difficult to describe the sound the truck is making.

 

I'll give that a try.

 

sounds to me the a/c compressor is engaging. mine does it, my 07 5.9 did it. normal.

 

Started mine today, had sat since Friday, with the ac on and it made a loud clunking noise a couple seconds after startup , sounds to me like it's gotta be the ac clutch

 

Mine does the same thing, Dealer thinks its the actuator for the auto dampers. Said he couldnt do anything until it actually breaks.

In mine it sounds like something stuck in the fan.