Roger :
Your description sounds like "spark knock" to me. Try backing off the timing
about 4 degrees and retest. (4 deg. may not be enough to eliminate, but should
make a substantial difference.) If that is the problem, you can either leave
the timing retarded (which may result in poor gas mileage, poor performance
and/or overheating), or use higher octane fuel.
Can't think of anything else that matches your description. Bearing knocks are
usually more apparent at low rpm, heavy load.
Note : diesel engines operate under conditions of what would be spark knock in
an Otto cycle engine (hence the 'dieselish' sound), but they are designed to
take it. Continuous knock will soon destroy your TR3.
Randall
59 TR3A TS39781LO
On Monday, August 21, 2000 6:36 PM, Roger Colson [SMTP:sassamon@mediaone.net]
wrote:
>
> Now
> I can hear a disturbing noise coming from the engine area.
>
> A friend has listened to it and is pretty sure that it is not bearing knock.
>
> He said to describe it as sounding sort of dieselish.
>
> The noise occurs after warm up and under acceleration. The cut in
> RPM will vary depending upon the road speed of the car. The higher the
> speed the higher the RPM the noise will start. Because of the changing
> RPM threshold I don't believe it is sympathetic vibration.
>
> I can control the noise by opening and controlling the throttle. I can get
> on the edge and by curling my toes get the noise at will.
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