Hey everyone! Just bought an 04 Hemi today with full service records and a clean history. It has 116k miles and I have a noise that developed tonite that I didnt hear all day since picking up the vehicle. It doesnt sound to be metal on metal, no tapping from either side of the heads, no pan knock or noise. I know that its not power steering or AC, which leaves the alternator. It sounds like its coming from the top of the motor at the front of the intake but I cannot isolate the noise....... below is a video where I start with the intake where the noise comes from, then I go to each head to show that its quiet. You can hear the coils/injectors clicking but thats it. Any ideas guys??? Im really worried and need some help! I did degrease the motor today and then sprayed it down at the car wash.....I did it with the motor off and the spray wasnt direct on any major parts but the alternator did get wet.....I was thinking maybe it was the alternator bearings going???? The video gives the slight sound that it is a rod knock but it is wayyy to fast to be that.....remember the truck is idling here guys.

 

Id like to add that from the cab of the truck and under acceleration it gets higher pitched with acceleration and turns into more of a whine. The truck runs excellent though. Idles perfect, and revs out fine. Oil pressure is slightly past the half way point. Ive listened to several videos and it doesnt sound like lifter tick either.... I am so worried that I just bought a truck with a broke motor. I took it for a 60 mile ride and drove it around town....I feel like its related to degreasing the motor and spraying it down...Anyone?

 

Well an update even though no one posted a response.......in my attempt to clean the engine bay.....the water that got in the alternator fried the bearing which made the motor sound like it was grenaded.....I figured this out by pulling the serp belt and checking pullies....only to find that even spinning my alternator by hand, it sounded like rocks were in there. I dont know if it was necessarily my washing the engine bay alone or that combined with the age of the vehicle and the 100 miles that helped but hey atleast my new truck will start out its life with a new alternator!

 

Glad it was something that's easy to fix. My old 4.7 developed a whine i never could fix after replacing all kinds of stuff.

 

Oh well that is was the alt. But at least you figured it out and fixed it.

Good job.