98 Impreza Outback:Broken Speedometer & Transmission Issues

[andymcp]

I purchased my 98 Impreza Outback Sport from a used car dealer in Maine
only a few weeks ago and put almost 4k on it driving it out to LA.
Soon after hitting Nashville, my speedometer became stuck at 40 mph. I
soon found out that when driving between 0 and 60 the speedometer
usually stays stuck at 40 and when going above sixty, giving the dash a
smack right above the speedometer would get it working but slowing down
below 60 it will sometimes (but not always) get stuck.

At around the same time this began occurring I noticed that my beloved
Subaru was also having difficulty shifting from first and would rev up
to 4 and wouldn't not shift until I let off the gas. This seems to be
an intermittent problem and since this and the speedometer both began
within an hour of each other I'm wondering if these two issues might
somehow be related?
Since the "smack" technique seems to work sometimes, I'm guessing there
is some kind of loose
connection. I'm wondering if this might be fixed through soldering so I
may try and give that a shot.

Unfortunately, this is my first car so I still have alot to learn but
any feedback would be greatly appreciated!
Thanks!
-Andy

 

[Michael Pardee]

I purchased my 98 Impreza Outback Sport from a used car dealer in Maine
only a few weeks ago and put almost 4k on it driving it out to LA.
Soon after hitting Nashville, my speedometer became stuck at 40 mph. I
soon found out that when driving between 0 and 60 the speedometer
usually stays stuck at 40 and when going above sixty, giving the dash a
smack right above the speedometer would get it working but slowing down
below 60 it will sometimes (but not always) get stuck.

At around the same time this began occurring I noticed that my beloved
Subaru was also having difficulty shifting from first and would rev up
to 4 and wouldn't not shift until I let off the gas. This seems to be
an intermittent problem and since this and the speedometer both began
within an hour of each other I'm wondering if these two issues might
somehow be related?
Since the "smack" technique seems to work sometimes, I'm guessing there
is some kind of loose
connection. I'm wondering if this might be fixed through soldering so I
may try and give that a shot.

Unfortunately, this is my first car so I still have alot to learn but
any feedback would be greatly appreciated!
Thanks!
-Andy

I suspect they are related. The common piece would be the Vehicle Speed
Sensor. If it were dead the "check engine" light would probably come on, but
it sounds like it isn't putting out the good stuff. My SWAG is that the
speedometer "freezing" is the result of a speedometer design meant to smooth
out little glitches in the VSS output, kind of like the satellite video you
see where the scene freezes until the data stream returns.

The transmission control is probably electronic (sorry - not very familiar
with Subies) and uses the same signal. I've seen a Buick refuse to come out
of first gear when the VSS failed - after all, what gear should it be in if
the speed is zero?

Unfortunately, I can't think of any good way to test that without replacing
the VSS. Maybe getting one from a wrecking yard and putting it in yourself
is a cost-effective approach, but I'd swallow hard before paying a mechanic
to put a new one in with symptoms this variable.

Mike