Weird Noise......

Alright guys, I've got a 2006 V6 auto. with no mods, just stock.

when i was driving home today, i started to notice a weird noise... loudest around 50-60 mph. it is a high pitch hum from either the rear end or the driveshaft. i had to have my foot on the gas in the 2000-3000 rpm range in order to hear it. any idea what it could be?

With out any mods I wouldn't know, I changed my gears and you can hear them, but I don't think you should be hearing a stock one.

Big Blue wrote:With out any mods I wouldn't know, I changed my gears and you can hear them, but I don't think you should be hearing a stock one.

i checked the rear end fluid, and it's low. i'm going to find out the type of fluid i'm supposed to put in there and fill 'er up this week

Are you sure its low? It should be 1/4 -1/2 inch below fill plug. I always just fill it straight to the plug though.

But honestly because the noise is dependent on ENGINE RPM you might wanna look at other things first. Mainly accessories.

Smokeurhonda wrote:Are you sure its low? It should be 1/4 -1/2 inch below fill plug. I always just fill it straight to the plug though.

It was rather low, I wanna say about a 1/2 inch, maybe more, below the fill plug.

Smokeurhonda wrote:But honestly because the noise is dependent on ENGINE RPM you might wanna look at other things first. Mainly accessories.

What do you mean by 'accessories'

Make sure its not an exhaust pipe or a hanger, I thought the rear was going out on a cruise 2 years ago, it was just a hanger, if you looked under the car nothing was close to touching any thing, but when the exhaust got hot it moved, after it cooled it went back to the way it was, and when I say after it cooled, I mean 30 seconds, so it gave me a fit, now that's an aftermarket system I had on, not stock.

Cdude2010 wrote:

Smokeurhonda wrote:Are you sure its low? It should be 1/4 -1/2 inch below fill plug. I always just fill it straight to the plug though.

It was rather low, I wanna say about a 1/2 inch, maybe more, below the fill plug.

Smokeurhonda wrote:But honestly because the noise is dependent on ENGINE RPM you might wanna look at other things first. Mainly accessories.

What do you mean by 'accessories'

Powersteering, alternator, ac comp, all that shit attached to you motor.

Were you running your A\C?

Big Blue wrote:Make sure its not an exhaust pipe or a hanger, I thought the rear was going out on a cruise 2 years ago, it was just a hanger, if you looked under the car nothing was close to touching any thing, but when the exhaust got hot it moved, after it cooled it went back to the way it was, and when I say after it cooled, I mean 30 seconds, so it gave me a fit, now that's an aftermarket system I had on, not stock.

i will do that!

Smokeurhonda wrote:

Cdude2010 wrote:

Smokeurhonda wrote:Are you sure its low? It should be 1/4 -1/2 inch below fill plug. I always just fill it straight to the plug though.

It was rather low, I wanna say about a 1/2 inch, maybe more, below the fill plug.

Smokeurhonda wrote:But honestly because the noise is dependent on ENGINE RPM you might wanna look at other things first. Mainly accessories.

What do you mean by 'accessories'

Powersteering, alternator, ac comp, all that shit attached to you motor.

oh well now i got ya. i got it up on the lift again and measured how low it was... it was about 3/4 of an inch below the plug. why is it so low? is there somewhere it could leak? I'm going to fill it up this week...

blown50stang1990 wrote:Were you running your A\C?

i did have my A/C running. how could that have caused the sound though?

You have to realize it's very hard to diagnose NOISES over the internet. Part of being car savy is being able to recognize and distinguish different smells, sounds, feels. We will help ya as much as we can, but if you can't figure it out you might just have to meet up with one of us.
3/4 of an inch down is a little low. The only places the oil can leak from would be the diff cover, pinion seal(the seal on the front on the diff housing where the driveshaft connects), axle seals (look to see if the inside of your wheels are greasy or wet) and the axle vent(which i've never seen leak.) Check that, other then that it might just be where the factory fill level is. Fill it till the oil comes out the fill hole, then let the excess spill out the plug it.

Easy way to tell if it is the a/c making noise. Drive so that the noise presents it's self. Then when you have it, click the a/c off. If it goes away you have your answer.

Also is the noise dependent more on vehicle speed or engine speed? Does it matter what gear your in? Explain the exact conditions in detail when it occurs.

Smokeurhonda wrote:You have to realize it's very hard to diagnose NOISES over the internet. Part of being car savy is being able to recognize and distinguish different smells, sounds, feels. We will help ya as much as we can, but if you can't figure it out you might just have to meet up with one of us.
3/4 of an inch down is a little low. The only places the oil can leak from would be the diff cover, pinion seal(the seal on the front on the diff housing where the driveshaft connects), axle seals (look to see if the inside of your wheels are greasy or wet) and the axle vent(which i've never seen leak.) Check that, other then that it might just be where the factory fill level is. Fill it till the oil comes out the fill hole, then let the excess spill out the plug it.

Easy way to tell if it is the a/c making noise. Drive so that the noise presents it's self. Then when you have it, click the a/c off. If it goes away you have your answer.

Also is the noise dependent more on vehicle speed or engine speed? Does it matter what gear your in? Explain the exact conditions in detail when it occurs.

i understand, and THANK YOU for your patience. it's kind of hard to describe a sound through the internet lol. i'd say that it's more dependent on engine speed. most prominent in 2000-3000 rpms. i mean i started noticing it when i turned my radio down at around 60 MPH. i'm going to mess with it tomorrow and try to see if it's the a/c and what not. and i'll get back to you. btw does anyone know what type of fluid i'm supposed to get? just the same that comes with the gears on american muscle? that purple stuff?

Should have a tag on the diff cover saying the viscostiy. Most likely it will be 75w-140. You can also use 85w-140 if you use lucas.

The dealership says you need to use the motorcraft oil... but at $30 a quart... its expensive...

I went with Amzoil when I put my tru trac in.

The dealership can stuff it. They also said I had to use their synthetic tranny fluid. 20 bucks a quart. I got good ol dino trans fluid in there and it shifts great. Only things I see that do require specific fluid are the auto tranny that require mercon 5. Even then you can use mobil one.