2007 Explorer V8 Limited 4x4 - Whirring noise from front left, goes away when braking

[RPFLimited]

As described, I have a very odd problem.

When I drive this 07 Explorer V8 4x4 (My mom's car, we love it.), I notice there's a slight whirring noise from the front driver's side wheel. As you go faster in the car, the noise speeds up. I did the neutral trick (noise still there when in neutral on the highway) and I've braked on it. When I brake, it goes away. But there's a bit of a shudder when I brake at the higher speeds and it's whirring like this.

I popped off the wheel and checked out the brake. Everything looks fine. Caliper looks okay (a very small chunk is missing from the top piston but otherwise okay) and the rotor looks great.

I put it all back together, and nothing seemed loose. Yet, on the highway, Im still hearing the noise (although it must be my head, because I think it sounds a little quieter this time...)

Any ideas? I thought maybe a bearing/hub assembly but since braking gets it to stop, I figured something wrong with my brake assembly. Perhaps a new caliper is needed?

 

[MotorCityFats13]

place this truck on 4 jack stands and then you can walk around it and get a good listen sometimes rotational sounds do not really come from where they sound like while in the drivers seat

 

[V8SHO]

My 06 Explorer sounds exactly like you describe, a humming/whirring noise that increases with speed. Caused by a bad hub/bearing assembly, very common on these vehicles.

If brake pad wear is even, then the caliper should be fine. Unequal tire pressure and unbalanced tires might cause vibration in the steering wheel as well.

 

[Explorer_PL]

Place the car on some safe stands or wood blocks as MotorCity said and get a mechanic stethoscope. I have 218k miles on my 06 and have gone thru more bearings than you can think of and every time I was wrong which one is making the noise.
In one of the cases I had a bad output bearing in the transfer case, and another time the front u-joint on the front drive shaft was shot and it all sounded like wheel bearings but were not, so there are many components that can go wrong. But up to 200k all the noises I had were just bearings, transfer case and the shaft were bad at about 215k.

 

[Tech By Trade]

Bet it goes away when you turn one way, not the other as well. Just fixed this same issue before Christmas. If its the right hub, the noise will go away when you turn left at speed, and if its the left hub it will go away when you turn right. I just replaced my second since I bought my truck. Replaced both fronts with dirt cheap Chinese models, first one has 40k kms without issue, second has only seen a couple thousand so far.

Have a real close look at the pins on the caliper when you have it apart. My top ones were frozen and the pads looked fine at the top, but the bottoms half was worn out. Ended up having to use heat to get them apart to replace the pads.

If its the front U-joint, its more of a clunking sound at low speeds that decreases as you increase speed. had to replace that a few years ago too.

 

[RPFLimited]

It seems to make more of a scratching sound as I turn, and for the first time, my truck had the ABS light pop up, as well as the traction control and some "wrench".

And in a very odd twist, the very rear (driver's side, way back by the liftgate) ?speaker? or whatever is in the little slotted vents - is making some strange hissing noise. Like it fades in and fades out.

I love this truck because it's an 07 Limited V8 4x4 with captain's chairs but the past 5000 miles (85k total) have been a headache!

 

[Tech By Trade]

Yep, another symptom when it gets real bad. The ABS ring is built into the hub and when it starts wobbling real bad it will throw an ABS failure. If you can find a real good code reader, it should tell you which sensor is throwing the failure, and that will be your bad hub.

 

[suzook]

It seems to make more of a scratching sound as I turn, and for the first time, my truck had the ABS light pop up, as well as the traction control and some "wrench".

And in a very odd twist, the very rear (driver's side, way back by the liftgate) ?speaker? or whatever is in the little slotted vents - is making some strange hissing noise. Like it fades in and fades out.

I love this truck because it's an 07 Limited V8 4x4 with captain's chairs but the past 5000 miles (85k total) have been a headache!

Truck is at that age age and mileage where things start to break. You could dump it, or be prepared for things popping up.