Whine sound when accelerating

I have been trying to find a whining sound that seems to be coming from near the alternator on my 2014. It starts at about 1100 rpm and is there on acceleration and when revving in park. When under the truck it can be herd but is very faint. With my head under the hood it is most noticeable near the alternator/turbo/exhaust manifold area. I used my stethoscope but it all sounds the same I haven’t been able to pin point one located with it.
So far I have checked the bearings on the dive belt system and the alternator bearing sounded like it was bad so I replaced it with a new alternator but the whine is still present. Does the alternator on these trucks always make a little noise as it spins faster? If not where should I look next for the sound?

The alternator should be quiet.

Check your tensioner (which is below the alternator) and the idle pulley (left side of engine).

Good luck. I’ve been looking for one that comes around like you’re describing. Mine almost sounds like the turbo, but it starts just before it spools. I haven’t gotten around to checking boost leaks yet because I’m leaning towards a pulley somewhere.

Any way it could be a water pump related noise?

Highwayman said:

Good luck. I’ve been looking for one that comes around like you’re describing. Mine almost sounds like the turbo, but it starts just before it spools. I haven’t gotten around to checking boost leaks yet because I’m leaning towards a pulley somewhere.

Click to expand...

I just started wondering this morning if it’s turbo related. Mine also starts right before the turbo starts to spool. Have you tried taking the belt off to see if it still makes the noise? That would tell us if it was a pulley or not right?

dummins said:

Any way it could be a water pump related noise?

Click to expand...

I’m not ruling that out. Does the water pump make a little noise as it starts moving water faster? It could be that. I loosened my belt and all the pulley bearings spun good and there wasn’t any play in any of them. But maybe I need to pull the belt off and start it for a second to see if that kills the whine.

I had this and it ended up being a manifold bolt had backed itself out, I swore it was a bearing and acted just like this.

Changed belt, tensioner, and idler pulley and there is no change to the whine. Tomorrow I’ll check the manifold bolts to see if one of them is loose.
if it’s not a manifold bolt I don’t know what to check next.

I had a 2014 ram for a while that had an annoying whine. I'm pretty sure it was the power steering pump because the noise changed slightly when you turned the wheel. Never did get it checked out/fixed before I sold it.

Never mind. You probably wouldn't hear that more on the exhaust side.