164S Under Hood High-Pitched Whistling Noise

["Rich Lasner" <rlasner@xxxxxxxxxxxxxxxxxx>]

Last week I noticed a high-pitched whistling noise coming from under the
hood of my 164S. I had replaced all the belts a month ago and thought that
maybe I had a bad pulley, or worse, a dying alternator bearing or water
pump. The noise increased in pitch and volume with more throttle, so I
suspected something directly tied to the rotating parts of the engine. While
looking under the hood, I rested one hand lightly on one of the engine's
chrome velocity tubes and the noise stopped. It seems that the last time I
had the valve covers off to replace the cams, I hadn't completely snugged
one of the Allen screws holding the tube in place (it's in an awkward
position between the tubes). It only took a little gap between the gasket,
tube and valve cover to cause a very noticeable problem. FWIW, this bit of
luck may have saved me a weekend's worth of  poking around.

Rich Lasner
92 164S
Mill Valley CA

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