Hi,

Two odd noises in my 91 318i Id like advice on:

1) When wet, if I go over a big bump or big puddle, Ill hear a knocking noise
somewhere between the rear passenger side of the transmission hump and the
rear passenger side wheel. Only happens then, so its not a terrible failure
of a component, justy noisy enough to be annoying WHEN it happens.

2) The second is an unrelated driveline whine. All fluids from the MT back
are dealer supplied BMW fluids, i.e. transmission and diff. It is simply a
whiny type of noise (not a bad one, just loud) very similar to that which I
hear in my father's 4cyl Toyota Previa (which is also RWD). I am wondering if
maybe a switch from the BMW fluids to some redline/mobil 1 synthetics could
help in that regard. It isnt really a big deal, but Id prefer to hear the
engine more and the driveline less...

Thanks!

JMH