2001 Buck Century-Just wierd or a junker?

It's got 43,000, mostly city driving with some brief freeway runs. Two
probs. First, it's using about a quart of oil every two or three
months. Not leaking on driveway and the car's not smoking. Inside of
the exhaust pipe isn't light grey but it's not sooty black either. Is
it leaking elsewhere or am I headed for a ring job?

Secondly, the Low Coolant light stays on long after other dash lights
have checked and gone out. After five or six miles of driving the Low
Coolant light goes out. There's plenty of coolant in resevoir and the
radiator. On secondary startings during the day, Low Coolant light
performs like other dash lights; unless over a long stop, then Low
Coolant light stays on for five or six miles. This is not an
intermittent occurence.

Anybody experience these symptoms? I suspect it might take a legit
mechanic days to diagnose?