Rear crank seal air leak 5ktq

[RYAN ALAN HOITINK]

Hello listers,

I have a very obnoxious noise coming from the rear of the engine front
of the transmission on my 5ktq.  I think it may well be the rear crank
seal wailing away, but I'm not really sure.  I tried the dipstick test,
and it changes the noise about half the time.  The thing is, the noise
isn't always present.  The noise only starts when the car is somewhat
warmed up.
Then, the noise will only be present from around 700 rpm to around 2500
rpm.  If i let the car idle, the noise is present, clutch in or out,
same noise.  If I put it in gear and manuall drop the rpms below 500 via
the clutch, the noise goes away for ever until I bring the rpms above
2000 again.  Neither the pitch of the noise nor the intensity change
with engine rpm.  Basically, either it's there or it isn't.  That's what
leads me to believe that the noise is cause by the rear crank seal
whistling.  Any ideas?

Also, if this is the case, has anyone tried to fix this with an engine
stop-leak product?  I thought this might refresh/expand the seal just
enough to stop the noise.  Might be worth a try.

Thanks in advance for any suggestions

-Ryan