Help me diagnose this sound...

[masphx]

Hi,

I bought a 1998 5speed a couple months back with 168,000 on her. Since then I have put 2,000 miles on the truck and everything seems fine. About 1,000 miles ago the truck started to make a strange sound. Can you help me diagnose it?

Here are the details...

-Normally makes sound after start up (first few miles of driving)
-Normally sound comes in at 2500 rpm (sometimes around 2000) and will only last a second unless I hover around 2500 rpm.
-Engine will not make sound while I just rev it.
-Comes from outside of vehicle (can hear it just as good from driver or passenger seat.)
-No power loss while sound happens. Truck accelerates the same.
-As far as I know sound appears throughout all five gears.
-After initial warm-up and first few miles drive sound ceases to exist except for a few times.
-No vibrations or shaking. Stick does not shake any differently when sound appears.


Here is the video. You can hear the sound at :20 while truck is passing 2500 rpm in first. Sound again appears at :28-:30 in second gear. I hovered at 2500 rpm for a few seconds. Again in third gear at :39 but you can barely hear it. Rest of video is me revving the engine at a stop with no sound and then accelerating though a few gears with no sound.

Sorry about the sound quality. Have tried a couple of times to get this sound on video but seems elusive. It is pretty noticeable first hand.


1998 4runner sound - YouTube

Hopefully someone can help me out and let me know what i should check. I just want to know what is going on with the truck and if something should be looked at before it fails. I might have the truck looked over by a Mechanic. Any good Toyota mechanics in the Phoenix area?

Thanks in advance for the look and the input,

Mason

 

[habanero]

That metallic rattle sound? The kind that makes me get under the truck and do a little thunking with a rubber mallet on places like the cat heat shield, bumper, brake dust shield, license plates, anything that can make that noise or look for little rocks (those make more of a tinky sound) in a variety of places?

 

[masphx]

That metallic rattle sound? The kind that makes me get under the truck and do a little thunking with a rubber mallet on places like the cat heat shield, bumper, brake dust shield, license plates, anything that can make that noise or look for little rocks (those make more of a tinky sound) in a variety of places?

Yes, that is the sound. I'm planning on doing that but this sound make me think its an engine or transmission issue since it make a sound on cue at 2500 rpm.

 

[habanero]

Could be just the right vibration and position at that rpm and load to make the sound.....
or it could be something else.

 

[A.Wilson013]

Could be just the right vibration and position at that rpm and load to make the sound.....
or it could be something else.

A friends Passport had the same issue. The mount for the Exhaust Vibration Dampener Thingy (Scientific Name) was cracked and at 2500rpm it would start vibrating like crazy. I knocked it off with a hammer and Viola! Then he sold it.