Well, my truck has 115,000 miles on her. Tonight i was changing the oil and had the oil fill cap off with the engine running. I could hear a metallic noise coming from the oil fill tube. If i put the cap on i could then just barley hear it but with the cap off it was pretty noticable and is not normal!! Sounds like two bolts clanging together. What could b bad? I always changed oil and used mobil 1 turbo diesel.

My 2005 has the EXACT same noise that you are describing... :confused: I have always wondered what the noise was... But it keeps going down the road, for the most part...

Anyone have any clue as to what it is? Bearing noise etc? Im leaving for a trip to pull some campers in a few days and will probably put on about 8,000 miles! If my motor is going out, i don't want to have it crap out on me during the trip!

probably just normal valve train noise

I think the oil fill tube dumps into the front cover. So what you could be hearing is noise from the gear drive.

Like I said, mine makes the same sound... But, the weird thing is it has made the sound since the truck was new! I wouldn't worry at all..

the duramax has always had a certain valve train noise that no one not even chevy can figure out the source. probably and hopefully nothin

Like everyone else said, these motors make a little noise from the getgo, so with yours having a few miles on it just means it could make a little more noise.

OK guys...I guess I'll take my chances. Just seems like with it being a new noise, that something could be wrong. Thanks for your opinions tho!

All diesels make this "signature" noise. Some research has been done a while back on using this "signature" to predict maintenance. I don't know if they refined it or not.