Help With Noise Needed !

Happy New Year!

My 2006 Taco is finally giving me a bit of trouble; she has developed a noise that was very infrequent last winter, but is starting to appear more regularly.

The noise is "typically" heard when it is cold, when the truck is at idle/park, or is moving slowly. Once I begin to accelerate it is gone. I have had the vehicle to my trusted local shop and they heard something but were unable to locate.

This morning I grabbed some audio which I will play for them next week but was hoping someone might have some idea for me. I cannot hear the noise when I am outside of the vehicle or looking under the hood. I have not crawled all the way under as of yet, and am beginning to suspect something near/in the drivetrain but since I can't hear it even when crouching down by the driver side wheel well... I don't really know.

I created an audio file in .m4a format for quicktime, itunes. I cannot attach that directly here, so I am posting a link where it can be grabbed from my DropBox:

https://www.dropbox.com/s/p1cyeaz1t5u7gdp/IMG_0893.m4a?dl=0

Or here:

https://onedrive.live.com/embed?cid=B6C3816BB9106218&resid=B6C3816BB9106218!21503&authkey=AKDSyw9E72LfO60

At :10 you can start to hear it, and at :15 it becomes more noticeable. I start shifting from Park to Drive and back - and it really sounds off at :35.

I appreciate your thoughts...

*PS The audio was taken from the driver's seat, with the door closed...

 

Can't access your file .... But if it's worse when not moving and lowest rpm - Could it be a whistle coming from a vacuum leak??

 

Is it a squeak, squeal, rattle, hum, ...? I couldn't hear it on my office computer, even if I could access the file.

 

It's a rattle.

 

It's probably inside the truck. I have a rattle behind my dash that I'm pretty sure is an unsecured wire tapping against the back of the dash. I also regularly have new rattles pop up from the glove box area. I open it and slam it shut a time or two and the noise goes away (shit in the glovebox moving/ rattling). Same with the catch all tray under my HVAC controls/ in front of the shifter.

 

Auto or manual ??? If it's a manual it might be the throw out bearing.

 

Here is the original video... I'm not sure how else to make the noise available for listening beyond what I have done here.

https://onedrive.live.com/embed?cid=B6C3816BB9106218&resid=B6C3816BB9106218!21508&authkey=AGfyg8-qxDlfaHg"

 

It is an automatic.

 

Ok, One far out guess .... I had a 1974 Monte carlo that had a "ticking" similar to what you describe. IT was a cracked flywheel. Check the flywheel for cracks + tighten any all bolts to the fly and tranny.

 

ok Finally heard the video. Is that an inside noise or from underneath ??? Any chance it's the fan / fan bearing / fan hitting something?? Pull out your glove box and cab filter and check inside for crap.

 

Not familiar with the tacoma automatic tranny but when my turbo 400 sounded like that it was a tranny pump. But mine did it all the time and got louder n faster as the rpm whent up.if i was hearing it right sounds more like a knocking sound.

 

It’s heard from inside. I’ve leaned down while looking underneath and did not hear it... planning on crawling under and having someone (competent) run the engine while I look/listen.

 

I'd check the heater fan / ducts first. Sometimes mice get in there and build a nest. Sometimes something falls into the space - stick from outside or a pencil down the defroster ducts.

 

Yeah that's definitely not a regular ol' dash rattle, and I also don't think it's driveline related since it also occurs at idle.

 

Does it occur with the HVAC fan off? (haven't heard noise)

 

That’s a good point - I failed to mention that it is present whether the fan is off or on. It was off for the video.

 

IIRC the fan can not be completely shut off - just turned to low. To prevent CO/CO2 build up in the vehicle.