Hi Mike,

Keep the timing belt on schedule, if it breaks the head is toast.
If you get the car, then you'll also probably want to clear the
EGR also which when plugged can raise crankcase pressure and
start blowing oil by the seals. I'm told that synthetic oil
doesn't clog up the works as bad as ordinary oil so switching
to that is probably a good plan.

If you get the car avoid the chinese made control arm/ball joints.
FCP has Meyle, German made control arms that I'm trying. They're
$60 instead of discounted Volvo arms $120 + shipping.
You can get heavy duty sway bar end links and heavy duty strut spring seats
from IPD (They are high mortality items and you don't want Scan-Tech there.)

What codes is it throwing? It's easy to check the OBD codes
just Google "Volvo 850 OBD codes"

I went from a 740 to this 95 850 NA sedan and like it.
It's a tiger in the snow with 4 wheel studded tires.

Bill