$100 if you can diagnose this whining sound... SERIOUS OFFER

[utahduramax]

2016 Sierra 3500HD w/6.6L ~120,000 miles. Ever since I purchased the truck, it's been making this intermittent whining noise. It sounds like it's coming from the drivers side, and it only happens when I'm idling or under ~1000 RPM. Turning the AC/blower off doesn't change anything, but when I move the steering wheel back and forth it fluctuates the frequency. I've included a video.

The first person to successfully diagnose the issue will get $100 sent via Venmo or Apple Pay. Successful diagnoses simply means it goes away after I try your proposed fix or you give some advice that replicates/eliminates the sound at will. Thanks!!

Source: https://youtube.com/shorts/kkb2thFQdnM?si=1iybS9k9km8HBMDP

 

[2004LB7]

Check the power steering fluid level and for excessive foaming

 

[utahduramax]

Check the power steering fluid level and for excessive foaming

I went out to check right after I read your comment. Everything looks fine to me, but it hasn’t been driven in a couple days so maybe that would explain the no foaming? The levels look fine to me though. Could it be old steering fluid? I included a video of me taking the cap off trying to show how much was in there. Thanks for the suggestion either way.

 

[2004LB7]

Even if it's not the source of the noise, that fluid needs to be changed. It's very dark.

You'll have to see about the foaming with the engine running, fluid hot and steering been cycled a bunch. Basically after a good drive. Pop the cap and take a look. Might need to do it with the engine still running so be careful

 

[utahduramax]

Even if it's not the source of the noise, that fluid needs to be changed. It's very dark.

You'll have to see about the foaming with the engine running, fluid hot and steering been cycled a bunch. Basically after a good drive. Pop the cap and take a look. Might need to do it with the engine still running so be careful

I’ll get on that asap!

I’m also wondering if you might be onto something..

I drove the truck right after I filmed that and when I started it, I heard that same noise but way weirder. It only lasted for a couple of seconds, and it changed frequency from high to low, then just went away for the whole trip. I only drove it for about 20 minutes, so I want to test it more, but I’ve never heard it sound like that.

Is it possible that opening the reservoir could have possibly done something??

The only other thing I can think of is that the truck has been sitting for 4 to 5 days, and it’s usually driven daily.

Weird though, right?

If it ends up being related to power steering, I’ll gladly pay up. That’s the closest I’ve come to anything remotely close to an answer. If it ends up being foamy, what’s the fix?

 

[utahduramax]

Even if it's not the source of the noise, that fluid needs to be changed. It's very dark.

You'll have to see about the foaming with the engine running, fluid hot and steering been cycled a bunch. Basically after a good drive. Pop the cap and take a look. Might need to do it with the engine still running so be careful

I'm really starting to think hydroboost unit or something related now. Every time the noise came on and I would look under the hood, the exact spot it would appear to be coming from is right where the hb unit is.

One issue is after looking around other forums, it appears that if the hb is going bad you're likely to have issues braking/steering, and mine are working just fine. My brakes feel perfect, and the steering is fine and only makes that normal whining sound when locked in either direction. I hear the sound whether I'm driving (seemingly only at low speeds) or sitting still with my brakes fully engaged, and pressing the brakes doesn't appear to have any effect on how it sounds. The only thing that changes the frequency of the whine is moving my wheel to the right or left. I can just be driving down the road and it will just randomly kick in, then just as randomly go away.

I did read one post where they said that air in the system can cause a whining sound, so I wonder if that correlates with that similar-ish sound I heard when I started the truck right after opening the reservoir? Like maybe I let some air out and that magically fixed it??? Haha if it did, I'm going to need your Venmo!

 

[SoCalMike]

I would check all you pullies and fan pulley. Also check the belt. I usually replace the belt and all pullies / belt tensioner at about 100k interval's. My fan pulley is still original at 230k miles and it is still good. Do a power steering flush and go from there. I flush my power steering annually.

 

[utahduramax]

I would check all you pullies and fan pulley. Also check the belt. I usually replace the belt and all pullies / belt tensioner at about 100k interval's. My fan pulley is still original at 230k miles and it is still good. Do a power steering flush and go from there. I flush my power steering annually.

Yeah, that couldn’t hurt. And judging from the color of the power steering fluid, it absolutely needs to be replaced/flushed. I actually didn’t know that it’s supposed to be clear in most cases! Mine is like a thick, dark orange.

Wow, 230k! Those are the kind of miles I’m hoping for! Are you saying you’ve never needed to replace yours? Or that because of your regular maintenance, you’ve been able to keep it original?

The last time I posted about this, someone else mentioned running the engine without a belt for a moment, the problem is that it’s so intermittent that by the time I turned it off and back on, the chances it would pop up in those few seconds are pretty slim. Even if I just knew how to make it happen reliably, fixing intermittent issues like this is always the worst.

I just have this nagging feeling that although it’s seems very minor, I’m putting off some sort of very basic maintenance or repair that’s going to explode into something much bigger if I don’t take care of it.

 

[SoCalMike]

Yeah, that couldn’t hurt. And judging from the color of the power steering fluid, it absolutely needs to be replaced/flushed. I actually didn’t know that it’s supposed to be clear in most cases! Mine is like a thick, dark orange.

Wow, 230k! Those are the kind of miles I’m hoping for! Are you saying you’ve never needed to replace yours? Or that because of your regular maintenance, you’ve been able to keep it original?

The last time I posted about this, someone else mentioned running the engine without a belt for a moment, the problem is that it’s so intermittent that by the time I turned it off and back on, the chances it would pop up in those few seconds are pretty slim. Even if I just knew how to make it happen reliably, fixing intermittent issues like this is always the worst.

I just have this nagging feeling that although it’s seems very minor, I’m putting off some sort of very basic maintenance or repair that’s going to explode into something much bigger if I don’t take care of it.

I never needed to replace my fan pulley. I just replaced my head gaskets and checked it was still good. No play.

I don't think you have anything to worry about. Just go over the stuff we mentioned and flush the power steering.

 

[N2BRK]

When my hydroboost was going on my LMM, I remember having to tap the brakes in a curve with the wheel turned (got cut off), and as I hit the brake the steering wheel tried to snap straight from loss of power assist. I don't know if that's a real "test" to perform for what's ailing you, but it might give you some insight as to the health of the hydroboost.

 

[SoCalMike]

From my experience when the hydro boost starts to go bad, they will leak from the bottom or start leaking in the cab where the shaft connects at the brake pedal. I replaced mine with an LML hydro boost and it was a good upgrade for my LBZ.

 

[NC-smokinlmm]

Does your truck have power steering assist? The trucks actually built in mid 16 and on had steer assist.

 

[kidturbo]

Over the years wrenching, I've found that a $12 stethoscope is the single best tool for locating mystery noises. Loose rockers, pumps, injectors, exhaust leaks, or a growling bearings, nothing will hone in on it quicker than a metal tube and piece of hose...

Duralast Stethoscope | AutoZone

www.autozone.com

 

[NC-smokinlmm]

You figure out if your truck is equipped with power steering assist?

 

[NC-smokinlmm]

Free diagnosis I assume… I don’t care about the money but why be a dick and offer it in the first place?