New mystery dry growling noise up front

[DaveH77]

Ok, at 284,000+ miles on my 2004.5, who knows what might rear it's ugly head next.
Made a 400 mile delivery to N Idaho, and it ran just fine.

Next morning it started making a new growling noise from up front like a subtle dry bearing or such.
Not loud but just noticeable above the usual diesel sounds. Only lasted a minute or so, then quit. Since it was a new 'condition' I did not like the sound of, did not drive it that day.

Same thing the next morning but i had the hood open. Odd, can hear it better in the cab. Can not pin it to anything specific in the engine bay with the hood open.

Third day, no noise! Ok, take it on a short run, but 3 blocks up it started growling noticeably while idling at the stop sign. Turned back to home but it quit as I turned around.

Several short trips with no noise, then a 10 mile run to pick up a delivery and it started growling while I was backing in to load. Again, only briefly, quiet all the way home.

First I thought it was the idler, an accessory, maybe the injection pump, upon cold start up, but the stop sign and delivery run were both after it had started to warm up.
Seems like it might cycle on and off related to temperature.

Does it sound like it might be the fan clutch? No physical play or leakage there.
Anything else come to mind?

I am not a "drive it until it develops" guy but I have a 100 mile round trip I have to make today, so time or miles might tell us more. Hopefully not!

Thanks, Dave

 

[Mark31]

Hot (shot) bearings in anything the belt turns? Idler, a/c, alternator, etc?

 

[petersonj]

I would remove the serpentine belt and rotate each component checking for rough bearings and / or excessive play.

- John

 

[chunter]

That is interesting, since my 2004.5 (I live in N. Id) is doing the same thing on sub 50s degree cold starts. The noise goes away once the truck warms up. I replaced the water pump, serp belt, belt tensioner and idler pulley on my truck as part of my routine maintenance (250k miles) this past June, but the noise only started happening last month. Hopefully your noise is the idler or belt tensioner and not one of the more expensive parts.

 

[crabman]

Power steering fluid.