AutoBanter - View Single Post - Metallic chattering sound

**GMach3**

"E Meyer" > wrote in message
...
> From your description, it sounds like a loose or damaged exhaust heat
> shield.
>
>
> On 4/4/07 5:39 PM, in article
> ,
> "Chicken-Fried Steak" > wrote:
>
>> Got a problem with my 1999 Mazda B2500 (Ford Ranger under the hood), and
>> before I take it to my "plug it into the computer, no error codes,
>> nothing's
>> wrong with it" mechanic, I wanted to run it by some people that know a
>> little more about vehicles. Here's the basics of my truck & the problem
>>
>> 1999 Mazda B2500
>> 4-cylinder engine
>> 5-speed manual transmission
>> 130,000 miles +/-, original everything (including clutch)
>> 2-wheel / rear wheel drive
>>
>> Problem: vehicle makes a metallic chattering sound (like someone with
>> steel
>> dentures chattering their teeth in the cold, best way I can describe it,
>> or
>> maybe like a dime rattling around in an empty beer can) intermittently.
>> Sound seems to be coming from under the floor boards, close to the back
>> end
>> of the vehicle. Sound is worst when there is a load on the engine,
>> especially in higher gears & when going up hill, or if I let the clutch
>> out
>> too slow when up shifting to a higher gear. Sound only happened once
>> when
>> there was no load on the engine. Engine sounds are normal, engine idles
>> within normal parameters (500-750rpms), accelerates well both on flats
>> and
>> up hill. No idiot lights have come up on my panels (and this truck is
>> like
>> a nervous child, if it thinks even the slightest thing MAY be wrong, my
>> dash
>> lights up like a Christmas tree). Sound happens more often at lower RPMs
>> (just before I down shift) or when accelerating suddenly.
>>
>> I had chalked it up to an old vehicle with a loose panel or something
>> else
>> that's pointless to worry about, until today when a friend (and former
>> mechanic) said it may be something in the driveshaft and/or rear
>> differential. At first I thought the worst this could be was that my
>> 130,000 mile clutch is finally giving out on me, even though it feels ok.
>> When he mentioned this, I had nightmare images of a bearing seizing up
>> and
>> my transmission blowing out as a result.
>>
>> Obviously to diagnose a problem, it helps to be IN the vehicle, but
>> anybody
>> want to shed some light on the above? Feel free to ask for more info.
>> I'm
>> just trying to get some feedback & suggestions before I take Chicken
>> Little's advice about the sky (and my driveshaft) falling.
>>
>> C.
>>
>>
>

I had the same sound on my '91 Ranger 4x4 until the heat shield fell off in
an intersection. Solved the sound problem! ;-)