2002 Chevy Impala with a low oil pressure what to do?
Before we look at causes of low oil pressure, a couple of
suggestions. Make sure you are using the correct weight oil and the
correct amount. In this vehicle it is more than likely 5w-30 and
4.5 or 5 quarts. Also remove the filter and install an AC/Delco
filter. The AC/Delco is a highly rated filter and is all I would
use in a GM vehicle. Make sure to use the correct filter. There are
many causes for low oil pressure but the most common is engine
wear. As the engine wears and gets sloppy, the pressure will drop.
But this is a gradual process, it doesn't happen all of a sudden.
If the oil pressure loss is sudden one, then we have to look at the
oil pump and pressure relief valve. It is possible the pressure
relief valve has some junk holding it partially open or the spring
in it is weak or broken. Only taking it apart will reveal the
answer. But before I do any of that, I would use a mechanical
pressure gauge and get an accurate oil pressure reading. It could
be a bad oil pressure sending unit or gauge giving you a wrong
reading. If there is valve or engine noise when the pressure drops,
then chances are it is a pump problem. One thing that will help is
to use a heavier oil in the engine, say 10w-30. This won't cure the
problem, but it will help for a while until the root cause can be