Then depending on how you feel about this Geo Metro (most folks love theirs!),
if you either do it yourself or have it done, a compression test will tell you
the condition of your valves and rings.
I, personally, held back doing mine because I wasn't sure I wanted to know how
bad they were!
If they were bad, it implied I had to decide on further fixing or not...decisions, decisions!
But - the compression test may show one or two of your valves aren't giving you
the efficiency you want.
If the rings are worn, you are not getting the efficiency you are looking for.
Does your oil turn black after a few hundred miles after an oil change?
There could be numerous other reasons for low efficiency, also....but -
A very easy, simple test may tell quite a lot - especially on an older engine
with that many miles on it.
Apparently around 140,000 to 150,000 miles on these engine is when the number one
exhaust valve starts going south.
Compression gauges are inexpensive when purchased at economy type stores like
Harbor Freight or Schucks Automotive. Maybe $30 at most.
Nice to have for any other cars you have or may buy later.
OK - I'll stop "preaching" now.
DoctorBill