Weird noise with vid

[Don W.]

I've finally got a vid which captures a weird noise my truck makes.

It sounds like something heavy like say, a breaker bar, rolling around in the the bed EXCEPT, the noise is inside the cab and only occurs briefly. The sound seems to come from under the dash, pas side and it's loud. Interestingly it does it mostly, but not always, on acceleration. If it wasn't so weird it would be funny. But it's NOT.

In the vid it happens on acceleration, and then faintly on deceleration then again near the end on acceleration. but this is not always the case. At times it seems to be at wheel rotation frequency but not always. Drove around some more after the vid and it seems to be working itself to the middle of the dash. :rotf:

And, yes, I know you're not here to hear it but maybe with the vid someone will have an idea. The vid doesn't do it justice, it's actually quite a bit louder that it seems in the vid. There's' nothing to watch, just listen.

BTW Before you ask, half-shafts are new,

Hope to get the truck up on a rack soon but meantime, I think my truck is haunted...

http://www.youtube.com/watch?v=vSTTTKY0GaU

 

[AZtyphoon]

Re: Weird noise with vid

Are you sure that's not knock? The way it sounds when you left off after acceleration sounds like knock to me. But hard to tell from the vid.

 

[FxsX24]

Re: Weird noise with vid

loose converter bolt?
had a similar issue on the noma

not that it is a common issue but what about the u-joints in the rear shaft?

 

[kentuc]

Re: Weird noise with vid

Flex plate.(flywheel)

 

[FxsX24]

Re: Weird noise with vid

Flex plate.(flywheel)

i figured if he checks the converter bolts he will find a flywheel issue if there is one

 

[Don W.]

Re: Weird noise with vid

I had thought of the flex plate but if it's the flexplate why is it so random? I woulda thought a flexplate would have self destructed by now, this noise is not new. Also when cranking there is no noise other than the starter of course. Wouldn't a bad flexplate make some noise either while cranking or just as it fires?

Although I will not stick my foot in it when cold so it's hard to tell it does seem to be "more active" when things are warmed up.

 

[JuStBlAzIN]

Re: Weird noise with vid

sound like a bearing is going out..and only hear it when extra pressure is applied. Like when down shifter or revved. Hope it is not. Can you hear it when you rev it is park? reve it to about 2500-3000. if you cant hear anything, then it has to be something in your drive train and not engine.

 

[jimmyz79]

Re: Weird noise with vid

Sounds like drivetrain.

Check U-Joints / rear driveshaft.
On your list I see that you have a gilbert propshaft, check to see if it isn't smacking the trans cable bracket.
Also, you said that the half shafts are new, could be defective...

 

[T-Bone]

Re: Weird noise with vid

You don't have a wheel lock bolt key in your glove box, do you?

 

[brandonb]

Re: Weird noise with vid

What about your down pipe/exhaust hitting the firewall or floorboard? There was a Syclone out here that sounded like that and that was his problem.

 

[WyoSyclone]

Re: Weird noise with vid

What about your down pipe/exhaust hitting the firewall or floorboard? There was a Syclone out here that sounded like that and that was his problem.

x2... check the downpipe bracket at the rear of the motor.

 

[Don W.]

Re: Weird noise with vid

Hmmm, could be the down-pipe, it is a 3". Truly checking that requires removal of wheel well, I will do that tomorrow. Glove box is empty. Pretty sure the front shaft is clear. Noise didn't change when I changed the half-shafts. (Brand new, not rebuilt) Going after the noise was the reason I change them actually so that was a bit disappointing. Have not been able to make the noise while revving in neutral.

All good ideas though. Hoping I find something when I get it up on a rack. Flexplate is still a possibility also. Any more ideas? Keep 'm coming.

Thanks all!

 

[turbodig]

Re: Weird noise with vid

Hmmm, could be the down-pipe, it is a 3". Truly checking that requires removal of wheel well, I will do that tomorrow. Glove box is empty. Pretty sure the front shaft is clear. Noise didn't change when I changed the half-shafts. (Brand new, not rebuilt) Going after the noise was the reason I change them actually so that was a bit disappointing. Have not been able to make the noise while revving in neutral.

All good ideas though. Hoping I find something when I get it up on a rack. Flexplate is still a possibility also. Any more ideas? Keep 'm coming.

Thanks all!

Loose torsion bar mounts?

Do you have an engine tie-down? If so, tighten it and see if the slapping goes away.
You can use an ordinary ratchet tie-down as a test, if you don't have one.

Put the camera down where the downpipe passes by and see if it gets louder.
Also, get underneath and grab the exhaust/DP and shake it... see if you can generate the noise.

Another option... have a friend drive, and listen with a mechanic's stethoscope to get a better fix on whether it's coming from the trans tunnel.

 

[bezerk]

Re: Weird noise with vid

****ed up cat?

 

[Don W.]

Re: Weird noise with vid

Loose torsion bar mounts?

Do you have an engine tie-down? If so, tighten it and see if the slapping goes away.
You can use an ordinary ratchet tie-down as a test, if you don't have one.

Put the camera down where the downpipe passes by and see if it gets louder.
Also, get underneath and grab the exhaust/DP and shake it... see if you can generate the noise.

Another option... have a friend drive, and listen with a mechanic's stethoscope to get a better fix on whether it's coming from the trans tunnel.

Torsion bar mounts? Noise doesn't happen over bumps as you can hear in the vid but I'll check them if I knew what to check. :rotf: Engine has solid mounts both sides, tranny mount is good. I've jiggled and shook the tail pipe but still need to get it up on a rack.

Can anyone describe what a bad (cracked?) or loose flexplate sounds like? It would seem that this is where all this is headed. That or the down-pipe. The fact that it's just so damn random that's driving me nuts. I haven't yet been able to connect it with anything, like speed or bumpy road or RPM or throttle. Racing today so if it's the flexplate maybe it'll let go.

 

[BoostedSUV]

Re: Weird noise with vid

Here a small list of things I've discovered making noises on my ty. 1. DP hitting frame and causing a rattle, 2. Broken motor mount causing engine to slam around 3. Broken torsion bar mount causing a thumping under floor board, 4. Cracked trans bellhousing making a rattle in tunnel, 5. Loose converter bolts or broken flywheel causing the flexplate to hit the bendix drive on starter 6. Energy suspension trans mount w/backing plate lifted transfer case too high and it hit the tunnel. Just some of my experiences. Gotta love these trucks!

 

[Don W.]

Re: Weird noise with vid

Like I said, I think mine's haunted. Gotta get that thing up on a rack. I can usually find stuff but this has me baffled. Really appreciate all the ideas.

 

[vanillagorilla]

Re: Weird noise with vid

Cracked flexplates usually sound like a constant ticking noise at all rpms regardless of what gear you're in or if you're moving. So I doubt that's what it is.

 

[skata]

Re: Weird noise with vid

could be a bad motor mount. motor rises when under heavy load, and fan hits shroud. check fan shroud for damage or rub marks.

 

[turboj91]

Re: Weird noise with vid

Seems to be something rotational. Noise starts when under a load. As brief as the noise is, it seems to get "faster" as the rpm's are rising and then quickly slows down when you let off the gas. Loose converter bolts is my opinion. No flex plate noise from when starting as the flex plate itself is still tight. Upon deceleration, when you hear the noise is the transmission down shifting?
Can you feel this in the wheel or your feet?