Low Oil Pressure

[Jwalkerblue]

Gauge indicated low oil pressure on 2002 4 stroke 225HP after 15 minutes of cruising (although audible alarm never sounded). Checked oil 1st time (no measurable oil on dipstick). Took off oil filler cap then checked 2nd time before filling - oil level was fine so did not add any oil. Started engine and low oil pressure bar on gauge disappeard. Could not replicate the problem and mechanic seems to think it was some type of air or vapor lock. Rather not wait for the problem to occur so any comments would be helpful.

[boats.net]

Might try changing oil and oil filter.