Rattle down low? (Full Version)

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Rattle down low?

  

MikeC4 -> Rattle down low? (9/26/2008 10:35:01 AM)

Hi all,

I have a rattle or clatter in my 1990. The car runs fine but, after it warms up, at idle, I hear a clatter or rattle down low around the trany but, not up higher in the engine compartment. It''s not a constant rattle, rather an occasional noise like a nut rolling around in side something. Then when I go to shut down the engine and the RPMs drop off, the clatter grows content and then stops with the engine. Also when I turn on the AC the clatter goes away for the most part. Pushing in the clutch has no effect on the noise either. I should mention that I have 6 speed trany. The car has 30,000 miles on it.

Any thoughts?

  
Curious George -> RE: Rattle down low? (9/26/2008 7:38:08 PM)

I had the same symptoms, but i have an automatic transmission (it does not make any difference... just FYI). You have one or both of your catalytic converters going out. Mine was the passenger side. I ordered a replacement from Summit for about $200. It was supposed to be a direct fit, but not quite. I had to get the end (opposite the manifold end) enlarged slightly so it fit properly into the mating exhaust pipe.

If pull your car up on ramps and tap each converter with a rubber mallet, you can hear which one it is. It will rattle. Be careful and do not hit it too hard or you may hear a heatshield rattle giving you false results. Just tap it a little, you will be able to hear it.

CG

cwb -> RE: Rattle down low? (9/27/2008 5:37:04 AM)

Is is a loose heat shield?

Same light vibration at the same rpm every time? Comin'' in and stoppin'' at about the same rpm every time?

mech259 -> RE: Rattle down low? (9/27/2008 2:48:03 PM)

Sounds like belt noise, spray some WD40 on the bely while idling. If the noise quits, probably the belt.

MikeC4 -> RE: Rattle down low? (9/29/2008 10:10:12 AM)

The rattle sounds like,(heaven forbid), a loose nut or bolt rolling around in the trany or something loose in the clutch area. Its not constant, it rattles a little then stops then starts,except when you shut it down. It like a ice cube in a blender getting knocked around.

  

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