my truck...93 4x4 xtnd cab, 3.0L, 5spd, CC, no A/C.
Noise seems to be coming from the upper center of the dash area that starts out like sort of a "clicking" or ratcheting sound at about 15-20 mph, then at about 30 mph it turns into this sort of a low to mid range frequency howl, and it gets progressively louder and higher in frequency as the speed increases...and it sounds like it clones itself with a noise very close in frequency, like there are two of the same noises playing in unison. It doesnt change if the clutch is engaged or dis-engaged. the noise reverses itself as the speed decreases and goes completely away at about 20-25 mph. This truck has a VSS speedo set up and, after disconnecting it at the tranny end and verifying a "no op" speedo needle condition by driving it, the noise was still there..no change. There are no codes stored in the ECU. I took off the front of the dash (radio, heater control bezel, lwr bezels, glove box, cluster garnish, then had the wife drive to duplicate noise, I got under the dash while car in motion to see if I could touch something that would make the noise change or stop...nothing...ECU does not vibrate during noises......All fuses and circuit breakers tested good, engine has no change whatsoever in performance.....it only makes the noise when car is in motion. It does not change with throttle pedal movement...and does not make the noise when parked and the throttle is mashed on.........W.T.F.????
I am at my wits end with this....and could sure use some new thinking on it, or would like to hear if anyone else has had a similar experience and what they did to fix it...pulling out my hair on this one...and I dont wanna take it to the "stealer" unless I REAAAAALY have to...thanks.

 

I'm able to offer no help whatsoever, however I can say that I feel for ya. Those noises DRIVE ME CRAZY and they are so hard to diagnose. Everyone I know tells me to just live with them, but I will settle for nothing less than perfection for my vehicle.

Good luck on figuring it out!

 

when i cant drown it out with my radio on 11, thats a noise I AINT Gonna live with...nor will my other half....

 

I found it to be the cup holder in the center of the dash.....the bottom folding piece.was vibrating ..even when it was slid in and not in use.......... CK it

 

Did I understand that what you are saying is that the noise frequency is a function of the driveline/rear wheel revs only?

If you put the vehicle up on jackstands, it sounds like you would expect the noise to track wheel/driveline frequency, although coming from the center of the dash. Might be an interesting test.

 

Throw out bearing?? They make some ˟˟˟˟ up sounds

 

Is the sound from inside or outside, not sure?
Is there a piece of trim on the outside of the windshield that is possibly moving? Take a piece of masking tape, tape the lower part of the windshield and drive the truck.

 

Sounds are really impossible to diagnose without being able to hear them #1

#2 even if you made a recording & hosted it, it would still be difficult. But that's my .02; make a recording & post a link to it. Anything else would just be like trying to catch a fart with a fish net.

 

Sound anything like this?
https://www.yotatech.com/forums/show...t=speedo+cable
click on the video image for video

 

oil the hamster wheel that powers these wonderful vehicals
it actualy sounds like a driveline issue, i relise that it sounds like it is coming from the dash, but could it be coming from the shifter (manual trans), if it is then ck the drive shaft and also the rear axel lube might be low or the wheel bearings going bad...or trans bearings going, trans/transfer case (4x4) low on fluid....ck any thing behind the clutch....front axel low (if ifs), front wheel bearings.

 

I would agree with the driveline comments. especially since you say it goes away when you mash the pedal. the noise is probably traveling through the shifter. good luck

 

my spedo makes a similar noise. i have found it to be the spedo cable.
3000watts of stereo system drowns it out justt fine ^^

 

i use to have a weird noise like that...found out it was the speedo cable....took off the gauge cluster,clean it off and put a tiny bit off grease on the back of the cluster and some down the speedo cable. it took a day or two to wrok in but no more noise now

 

I remember watching an episode of "Top Gear" once where Jeremy was driving yet another in a parade of fancy cars and during the entire trip there was a whistling/tapping noise that was driving him crazy.
After the trip, evaluation of the car, and during the wrap-up he said how it was later discovered that one of the mechanics had bent part of the windshield wiper causing it to catch air and vibrate.
Long shot on your problem, but possible I suppose.
Just another WAG, but have you tried changing the settings on the heater fan from outside source to inside or vice versa? Run the fan from low to high and see if anything happens? I once had a bunch of GD elm seeds that somehow managed to get past the intake grate and had gotten into the ducts. They eventually broke up and made their way out, but they were a noisy hassle until then.
Other oddball possibilities:
loose intake vent cover? loose hood trim pieces? loose windshield trim pieces? the PITA cup holder that is more trouble than it is worth (I know I hate mine, pieces always falling off and when it does work it gets in the way of all the heater controls )?
Hope you figure it out before the big hammers come out of the tool box

 

My freinds dakota does this, and I think it may be an exhuast leak, the sound it just travelling a different way!!

 

nope...will try to video later and post it here

 

will check out the exterior trim and wipers today...hadnt thought of that...i may put the truck up on jackstands like someone else suggested and have mama go through the gears to see if it makes the noise...I will point the car AWAY from the garage...just in case....thanks for the tip...much appreciated

 

3 months ago had it lubed, oiled, & filtered so doubt if its low fluids or lube... but thank you for your reply...this one is crazy!!

 

cup holder is out of car...still got the noise

 

sounds like its inside, but you know how noise travels...will try the taping trick on the trim...as soon as it stops raining so the tape will stick. Thanks for the tip....anything is worth a try at this point