Re: Return of the Rattling Spider Thread...

[Simon Favre <simon@domain.elided>]

Carlo, if I'm not mistaken, your '86 Spider Quad has a catalytic converter
in the spot the early cars had the infamous "front resonator" mounted. The
pre-cat front resonators are notorious for getting rusty inside then making
that buzzing sound around 3000-4000 RPM. If you do have a buzz coming from 
the ventilation system, maybe you could verify it by plugging up the air
inlet at the front of the car (not the one the engine breathes thru). ;=)
The resonator buzz is easily verified by driving next to a freeway K-wall,
or even by stopping the car, opening the door, leaning out till your ear
is near the ground, then revving the motor.

Annoying noises can be the most irritating part of owning a classic car.

Carlo.Cardilli wrote:

>This is a repost - turns out my postings were being discarded as my
>administrator "modified" my e-mail alias .. grrrr.
>
>Simon Favre <simon@domain.elided> wrote:
>>Subject: Re: Return of the Rattling Spider Thread...
>>My "usual suspect" for a buzzing noise at 3000 RPM is the front resonator,
>>but you've already eliminated that one.
>
>'scuse the ignorance but what is the "front resonator"?  I've been trying
>to figure out the cause of a loud annoying rattle at almost exactly 3000
>RPM in second gear too.  Sounds like it's coming from inside the center air
>vent.  Similar buzz but much less pronounced also in 5th at about 4500 RPM.

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