I bought an '89 Dodge B250 Van with the 5.9 L gasoline engine (throttle body
fuel injection). It's got 123k on it.
The vehicle drives and sounds great, starts right up even after sitting,
doesn't use any oil -- only problem was that after driving it a while, the
oil pressure would drip way down and the van would stall.
So, I replaced the oil pressure sender, then the oil pump. No change. I
even installed a good mechanical oil pressure gauge.
When I first start it (and the viscosity is high), it's right up around 60
psi. After I'm driving for 15 minutes or so, it's down to 40. If I come to
a stop at that point, it will drop to 20. Drive it a bit longer and come to
a stop, and it falls right down to zero.
At this point I'm guessing -- crankshaft? What would cause that?
Related question -- can that be done from the bottom without pulling the
engine? I was planning on replacing the timing chain anyway, so it's not
that much more a big deal to pull the transmission--I just don't want to do
the job and discover it's something else entirely.