please help diagnos noise

[srv1]

when truck sits over night,and outside temp is around or below freezing the next day I start my 2004 1500 5.7l and it has a loud howl for a few sec.,only happens at first start .by the time I can get my old a** out there to scope around its gone.i am suspecting water pump but there are no other signs.i recently relaced idlers and tensioner and all other acc. pullys were quiet .any help would be greatly appreciated

 

[srv1]

forgot to mention I also put a new belt on though it does not sound like belt noise.

 

[Octane]

forgot to mention I also put a new belt on though it does not sound like belt noise.

Accessory bearing noises?

 

[OCDTech]

If its a roar, fan clutch locking up, not supposed to do this cold but i've had many do it.

But if not that air rushing roar noise, then i go with @Octane , such as water pump or altenator. One way is to remove belt, wait until morning crank, see if noise still there. I usually wouldn't recommend this but if you don't let run for more than 10 seconds 15, not going to hurt anything. Just remember water isn't circulating. While belt is off, and engine, spin said accessories, see if you hear a weird noise, think vibration or "skateboard wheel roar"

 

[chrisbh17]

Like this? No idea what it is. It doesn't do it at every cold start so it's hard to diagnose. Haven't even bothered bringing it to the dealer because I'll have to leave the truck there overnight, get rides all over the place only for them to not hear it or tell me it's normal. My AC compressor whines with the AC running so I'm wondering if it's related and just hoping the whole thing breaks while under warranty.

The video is a cold start of the engine but you can hear the whine too.


Sent from my Pixel 3 XL using Tapatalk

 

[Travelin Ram]

Yeah, absolutely pull the belt off then start her up cold. Then you’ll know for sure if it’s internal or external.

If you can get someone to assist and record the sound to post up for people to hear you’ll likely get someone who recognizes it.

 

[srv1]

thanks for the video,however the howl I have is louder and happens as soon as I start it cold and only lasts for 3-5 sec.if I shut it off and start it again,no noise.only after truck has sat for a while and its cold out.if it gets up to above freezing temps outside,no noise.i am getting ready to go out and pull off the belt and start it and see what happens.its 18 degrees outside and I do not have a garage,this sucks.sorry to hear that noise coming from a newer truck like yours.diagnosing I have learned is harder than the repair.

 

[Karlsweg]

Fan

 

[chrisbh17]

Fan

Yes, Ive read that. Something about the viscous fluid in it being so thick that it causes the issue until it warms up enough to flow better. That fits more with what the OP describes their noise as.

 

[MikeT]

My wife's 07 Dakota does exactly the same thing, loud Roar on start-up when cold. Lasts about 10-15 seconds then noise stops. It's the fan clutch locking up. Doesn't do it in warm weather. We just ignore it.

Mike

 

[srv1]

I am suspecting fan clutch.can anyone tell me this,with truck off and sitting overnight,if I try to spin my fan by hand,what should it do ?should it spin at all?

 

[Legal Bill]

Just another diagnostic tip. You could remove the belt, or loosen it enough that you can turn all the accessories by hand. Get a feel for them when they are warmed up. The next morning, open the hood before you start it and give everything a turn and see if anything feels different.