I bought recently a 360 1975 Dart Sport,
107K. The oil light was flickering at idle
sometimes, so I installed a gauge. It dips
as low as 12-15 PSI sometimes in gear,
when it is hot. I am told that there is some
oil plug in the block that may have fallen
out and might be causing this. Is there a
way to check this easily?
There are three plugs that are pressed
in. Two are up front, behind the camshaft
thrust plate, and are backed up by the
plate itself, so it is unlikely that this is the
problem. (Some years, the factory even
omitted these plugs, yet some years they
were pipe plugs).
The one that it sounds like you are
referring to is in the rear of the block,
installed vertically in an oil gallery. You
can easily check this after removing the
oil pressure sender, all you need is a coat hanger
wire, see drawing, above. The bad
news: If this is missing, oil bypasses the
filter, which is not great for the engine’s
health, but actually increases the pressure
a tad, so I am doubtful that this is your
problem, although dirty oil can rapidly
wear the main and rod bearings…which
brings me to what I predict is the root of
the problem:
The engine needs a bearing job. You
can do this in the car (drop the oil pan), if
the crank isn’t scored you’ll be good for
many more miles. A new oil pump at this
time would also be a wise move.
