seeking advice again

[Clark]

Hey guys I'm stuck trying to figure this dilemma out. I have this intense loud humming noise
That starts at 30 mph and stops at 45 mph my engine sounds like a jet.
I changed my fan clutch " because I thought maybe that was the problem" and while doing so I changed my water pump too. But the noise
Hasn't disappeared. I've changed the front and rear differential fluids along with my transfer case.
I service my transmission yearly, my bearings are well packed . All in all my h3 runs great. she has 150k miles on her.
I've read all the threads concerning my situation " and there are quite a few" but with no outcomes.
Can any of you outstanding members help me out here? Please!

 

[Jeepwalker]

Just a couple thoughts, w/o hearing anything:

1) Could it be something along the lines of air resonance through the intake or with filtration (some vehicles can get loud). I've heard some vehicle 'howl' fairly loud at certain RPMs like you describe due to intake resonance ...or does it sound more mechanical?

2) Are there any grommets in the firewall which have been knocked loose (open) and allow more noise into the cabin than before (making it 'seem' louder than it used to be)?

 

[Clark]

Its a sickening sound. at idle my engine is really quiet. no trembles or anything else. But the howling starts at 30 mph and disappears upon deceleration. And quiets down at 45 mph. My next step is to take off the heat shield over the manifold,
and check the manifold gasket and check for cracks on the manifold itself. But there is no exhaust smell at all.

 

[3Hummers]

Do you have an after market cold air intake on it?

 

[Traxx]

Howling noises are usually a bearing. If it stops on decel then I would check pinions and the front cv.

 

[Happy Hummer]

Are you referring to the heavy jet like sound of the fan clutch, because I replaced my fan clutch just this summer to and boy does this HD fan clutch sound like a jet engine when it is cold lol!
Once it warms up for a few minutes of driving it mellows out.

 

[DJB]

If the noise lets up when decelerating you most likely have a differential pinion bearing on the way out. Since you've been replacing parts on the front of the vehicle I'll take a guess and say the front one. Been diagnosing and repairing cars & trucks for 45 years; have seen this hundreds of times. If you're sure that it's in the front, remove the front driveshaft, lock the transfer case in 4 high and take a spin. If the noise is gone, bingo! Won't cost you anything to try but your time.

 

[Clark]

Yes I do have an aftermarket cold air intake. And ok I'll take the front drive shaft off and lock the transfer case
in 4 high I'll give that a shot. Thanks guys for your advice I really appreciate it very much

 

[Clark]

Are you referring to the heavy jet like sound of the fan clutch, because I replaced my fan clutch just this summer to and boy does this HD fan clutch sound like a jet engine when it is cold lol!
Once it warms up for a few minutes of driving it mellows out.

yes I could deal with the warm up sound. But it's the sound I'm getting when I'm driving.

 

[Happy Hummer]

I'm going to say the front pinion bearing is remote but possible. I've had a pinion bearing go and it is a constant rotational hum no matter the speed I was doing. Again it's possible but I would think it would stand to reason it would start at say 5mph and continue... getting louder and more intense. I've been on the highway blazen a trail and you could feel, hear the bearing roaring.
I've also had carrier bearings fail and axel bearings. Front driveshaft rear most bearings are typically a bird cage kind of crow, screeching.
Could be a half shaft.

This is the trouble with diagnosis over the web. Maybe make a video.

 

[Happy Hummer]

By the way, what fan clutch did you install?
Could it be that said fan clutch is what is causing the issue?

 

[Clark]

By the way, what fan clutch did you install?
Could it be that said fan clutch is what is causing the issue?

Hayden 2787 since I installed it and the water pump my truck runs cooler.