Sounds like a incorrectly timed injection pump or
one seriously tired turbocharger! You said you
recently bought/acquired it? Ask the seller if any
work had been done on these areas,that is if they
answer the phone! Call from another number!

OP said Portland. Which , like San Francisco, is more or less sea level,
varying by a few hundred feet. What blows my mind about this, is - If
you're used to driving in San Francisco, what does a "very steep" driveway
look like? As far as I recall, ALL of San Francisco is very steep. Except
the bridges.

Which leads us to another possibility. San Francisco can be hard on
transmissions. Of all the pieces on the 300s, the auto tranmission is my
least favorite - someone once called it a very beautifully engineered copy
of a very ugly Oldsmobile transmission. It would be real helpful if you
could describe the problem a bit better.

Turn off the radio, roll down your windows and listen as you go up the
driveway - do you hear tire spin? If so, you know why you were able to get
the house - no-one can get up the driveway without four-wheel drive.

Or does the engine still rev with no tire-spin noise as the car comes to a
stop - if so, suspect the transmission is getting tired and is slipping.

If, on the other hand, the engine slows to idle speed as the car slows to
a stop, the tires are gripping, the transmission's not slipping, you're
just not making enough power. Which, as your top speed is about 80 is a
possibility - the turbo-diesels in good tune will blow past 80 pretty
comfortably, and really should have enough low end torque to climb most
reasonable surfaces.

If you hear tire slipping, there's still one other possibility. Steep
winding driveways under rainy conditions often get a thin layer of silt
runoff on them - which is slippery. Clean the driveway.

Conrad