'07 5.9 auto, when standing in front of the radiator while running it sounds like a bad bearing sound, but if I stand off to the side it sounds like a normal running Cummins. I have owned the truck for a year and it has 36,000 miles and has always sounded this way, but yesterday I noticed a whirring sound when cold that is dependent on rpm. So I am wondering now if the noise I grew accustomed to and this new noise are something I shouldnt have been accepting as normal. Are the power steering pumps noisy or are there fan clutch issues?

 

Water pump? Tensioner or idler pulley?

 

Water pump is only a few months old. Possibly the tensioner. What should I do to diagnose?

Also, to clarify, when standing in front of the grille, this truck sounds more like a 6.5 GM diesel than a cummins, but by the fenders and how it runs, its def a big C.

 

I would remove the serpentine belt and then start the truck to see if the noise is still there. This will narrow things down considerably.

 

Then turn all accessories by hand and see if you can feel the bad bearing.

 

A mechanic's stethescope would be helpful too. Make sure you don't touch it to anything that's moving though. Seriously, I've seen it done.