Re: Oil Pressure fluctuates on my manual gauge.

Posted by sgtslag on Apr 27, 2012; 3:17pm
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/Oil-Pressure-fluctuates-on-my-manual-gauge-tp3944323p3944427.html

You stated, "...manual gauge that I put on the right side..."  Do you mean that the oil pressure gauge is a mechanical, Bourdain Tube type, as opposed to an electrical gauge, with a powered sensor?  If it were an electrical gauge, I would suspect a bad connection between the sensor, and the gauge, or else a poor connection between the gauge and the battery.

Momentary drops in oil pressure, likely will not damage the engine, as long as the pressure rises immediately (oil leaves a film on surfaces, by design, to provide lubrication on start-up, when there is no oil pressure, preventing excessive wear).  The other potential cause, would be a missing tooth on the gears that drive the oil pump:  when it hits the flat spot (missing tooth), pressure will momentarily drop, as the pump will briefly stop turning.  Does it happen in a rhythmic pattern, repetitively (assuming constant engine velocity -- idle)?

I would suggest pulling the oil pump, and test it as per the FSM:  check the gears for wear, test the gaps in the rotor with a feeler gauge, check the O-rings, etc.  Better to be sure, than to risk turning that running engine into scrap metal.  Cheers!