Help Diagnosing a noise

Ok here is what I have happening. I have a 2006 Double Cab V6 auto with 35000 miles. I hear a noise first thing in the morning and only in reverse, like a rough grinding noise only for a few seconds and goes away. In only happens when you First hit the pedal for accleration, then stops. Seems to hear it more in cold mornings. Its not a brake squeak, i saw the TSB and dealer doesnt think its that either. Dealer has had it a few mornings, and hears the same noise, only by the time he gets it on a lift, you cant duplicate the sound. Says it might be one of those things it has to get worse before you can fix it. To me, it only happens in Reverse and after its sat over night. So could it be a fluid problem in the transmission?? Also sound seems to be coming from the front of the vehicle not the rear, So I thought maybe rear differential since fluids were changed at 30,000 and it has an LSD, however the sound would have to carry up to the front somehow. At a loss, but definately a grinding/rubbing sound. Should I ask they change both the transmission and differentail fluids and see how it goes? Again, it doesnt happen when in drive, only in reverse, and only when you first acclerate., if you dont hit the gas backing up, you wont here the squeak, thats why we ruled out brake pad/rotor problem? Any suggestions?

 

Any guesses?

 

The ABS will do a self test?

 

Belt pulley?

 

I had a 2002 Accord that did that. You could hear it easily, but I've never heard that noise on my Tacoma.

 

Would the ABS or Belt Pulley only effect it while being in Reverse. Because with all conditions being the same, if you put it in drive the noise will not appear, only in Reverse?

Chris, the dealers first thoughts on it were something about an ABS motor?? What is the function of it?

 

I think the ABS does in fact cycle first thing after you start the engine and engage transmission. I seem to recall hearing something about it and I can often feel it all my vehicles (Accord, Pilot, Passat and Tacoma). It is a very low level growl sound, then stops.

 

Check this out, i did a small write up a few weeks ago about a simular noise that i was having.....iv'e seen a lot of people with this noise maybe make this a sticky, or at least put it in mods!!

http://www.tacomaworld.com/forum/2nd-gen-tacomas/26317-vibration-when-cold-fix-pics.html

let me know how it works out..

 

Just wanted to update, dealer found the noise and its just like ballon said. Its the Air Intake Hose. There is a replacement part, but basically it seems when cold, you need that gasket on it around the body. Anyway Dealer replaced mine and all is fine again.

 

Nice!!! I didnt know there was a TSB on it until last week, after i fixed min!!! Plus took me 5 mins instead of at dealership all day. Glad you got it fixed

 

i have a similar problem with my 2007 tacoma. when i go into reverse and give it a little gas i hear a loud clicking noise. it only clicks once but its loud and it comes from the front left of the vehicle.any ideas?

 

The 2 things I would look at is the TSB for Brakes and Rotors, or this Air Intake Hose. Mine noise was only in the mornings and only on accerelation in reverse, dont know why mine didnt do it going forward. I guess cause if you park, most of the time you are backing up! But mine was the Air Intake hose, rubbing /vibrating/noisey?

 

Can you post a pic of what you are referring? What part you replace?

 

For a picture, ballon has a link above. Click on his link, and for me anyway it was the second picture. Its the Air Intake Hose, that goes from the body of the truck (seen in the picture) to the housing for the air filter. Apparently, right where the air intake hose attachs to the body, it must not be a tight fit or something, and when you first accerlate it makes a rough sounding weird noise. If you wrap it in a gasket, noise goes away. Check out the picture in the link above.