Front end high pitch whine

Hey guys I did a quick search but its tough to search from the phone so I apologize if the answer is right under my nose.

I noticed a high pitch whine today coming from the front end. It's while rolling. While hitting the gas or brake or anything it still whines. It's tough to hear in the open but is ear splitting while going through a parking garage. Very high pitch. What is going on?

 

bump for an answer

 

been driving around the parking garage in circles cause it's the only place I can hear it well trying to figure it out. The only thing to add is that I THINK it's coming from the passenger side.

 

Dunno if its relevant but... When my replacement alternator failed and started overcharging the system. I had a noticeable high pitch whine coming from the engine bay. almost like a SC whine.

If the whine is constant, it has to be something that is rotating...

 

It's constant only when the truck is moving. When at a stop or parked it does not make the noise.

 

could be the wear indicators on the front brake pads to where they are just starting to touch?

 

would the wear indicators whine even when not braking?

 

not sure on the taco's but on my old buick they did

 

My truck does the same thing but only between 15 and 40 mph. It sounds like it is the front passenger side also. I have no clue what it is.

 

I'm not sure if it has a top end on mine. I'm not sure if it stops or if it's just wind noise drowning the sound while I'm going down the highway.

 

Mine did. It's tough to explain without looking at it but there's that little lip of rotor on each face that isn't contacted by the pad so it doesn't stay polished and will rust. I know the 6 lugs have a completely different caliper set up but on mine the indicator was hitting that little rust lip when rolling and when I touched the brakes the pad would move inwards enough to not hit the lip and actually stop squeaking. It was driving me nuts so I finally pulled the front wheels to investigate and this was my discovery.

 

Does it change pitch with road speed or engine speed? Does it change volume/pitch when cornering left or right?
Road speed changes= driveline issue.
Engine speed changes= engine issue.
Inspect your brakes pads for thickness and your wheel bearings for excessive play JIC.

 

No changes that I can tell. I'll get on the brakes as soon as I get a free minute.

 

There has to be some kind of change. Nothing rotates at the same speed constantly. Focus, Daniel-san!

 

is it your turbo?

 

Well I can only hear it well when I'm going through the parking garage It's tough to hear going down the road but it's there. I'll focus

 

Keep in mind the pads are always a hair's width from the rotor. You might even hear them touching the rotors at low speeds. So if your pads are down far enough, the wear indicators will always be in contact with the rotor and will "squeal" when your Taco is in motion.

 

Check the heat shield on the inside of the rotor. Could be bent and touching the rotor as it spins. Can be annoying as hell.

 

Very true, but it makes a loud, scraping noise and not a high pitched squeal. Trust me, I just learned the hard way when I installed my LR UCAs and Toytec coilovers.