I just purchased a used 96 SR5 4x4. When I drive around town, I hear a persistent high-pitched rattling sound coming from underneath the body. It's mostly distinct when passing a building or sidewalk where the sound can reflect. I've sat on both sides of the vehicle and cannot discern which side it's coming from, though it sounds as though it's coming from the front end.

At high-speeds I cannot hear anything (rattle drowned out by road noise & wind). It rattles when coasting, when accelerating, and when braking. It does not rattle when stopped or idling. It rattles w/ and w/o the front hubs engaged. I have tried pinging on the front end at various points but haven't been able to mimic the high-pitched rattle -- the sound is almost like a small hammer rapidly hitting metal on the front end. The rattling is not a consistent sound, i.e. I hear it all the time but it is not rhythmic (sounds like someone tapping morse code), the rattling does not get louder nor does it become faster when I change speeds.

My friends have suggested that a) a running board is loose, or b) someone got stuck in the vehicle when it was manufactured and they've been trying to use morse code to get out ever since. In short, I haven't received any useful advice.

If anyone's experienced a similar problem, knows of a similar posting, or has any ideas or questions about what I should do (I would be willing to make a recording of the sound, if possible), I'd certainly appreciate any help.
Thanx,
Nate

 

Not sure if this will help but check the heat sheild on the catalytic converter. Sometimes they rust where they mount and rattle. Usually you will hear it when you the rig idles too. Anyhow good luck.

Rick