I once had a similar noise situation.... The problem was a worn cam
keeper. (The cam keeper is the metal plate that fits on the front of
the engine and covers the hole where the cam is inserted into the
block.)
If the keeper is worn enough, the cam can slide forwards a little too
far for the health of cams and tappets. Tappets, properly operating,
rotate with use. (There is a very interesting concave grind applied to
tappets that make them rotate in their cylindrical holes as the cam lobe
strikes the bottom of the tappet.) This rotation helps with the tappet
lubrication. Some tappets have a flat side.... to improve lubrication
I think... but the flat side can also cause tappet noises to appear
intermittent as the tappet rotates in its cylinder well.
At any rate, if you are having noticable tappet noise, it can be a
precursor to major cam damage. If it were on my car, I'd inspect the
cam keeper for wear....and the cam lobes too.
Yes, changing tappets might help, but if the cam lobes are damaged, your
(twelve) new tappets won't last long.
-skip-
(on the right track?.... maybe, but if the oil is merely masking the
problem, then no: Not the right track.)
fmags@cox.net wrote:
>
The frequency of the noise did increase with increased rpm. I
> gave it several hard raps of the throttle and the noise went away. Gave it
> several more raps and it came back to various degrees with more or less noise
> and a little rough running of the engine, and I got the noise to stop again.
>
> Does it sound like I am on the right track?
>
> Thanks,
> Frank
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