<VV> too much trans fluid causing an ominous knock?

[cmot at ix.netcom.com]

A leaking vacuum modulator will allow oil to be burned creating carbon
deposits that can may cause a knock. Undo vacuum line at modulator and check
for any oil present at port or in the line. I used to double check them with
a handheld vacuum pump. Also over rich or leaking carbs (as in a dripping
main jet at idle which is high float level) will cause a similar carbon
buildup. Used to see this problem on many makes of vehicles/engines, leaking
Holly carb power valve diaphragms were a common source of this problem on
some model vehicles. It can cause a carbon buildup on the back of the intake
valves which I have seen 3/4" thick. It can suddenly break loose and cause a
knock that sounds like a broken piston. If you have that buildup sometimes
it breaks loose after a extended storage on restart. An old mechanics simple
cure is running water slowly through the carb intake at a high idle
1500/2000 rpm. I had a device with about a .040" hole in a container that
ran a stream in the venturi (only during the high rpm). The water/steam in
the combustion chamber breaks up the carbon and it will come out the exhaust
in small pieces. A quart in each primary usually does the trick. Beats
tearing the heads off to decarbon.
Chet Motyka