Greetings,
My oil pressure gauge has been reading dangerously low within 3-4 minutes of a cold start. The needle borders the caution zone at idle and has a tendency to dip into this zone under acceleration. First couple of minutes it will read fine, but the minute the oil warms up the pressure dives. Before this started occurring, I had noted a few random occurrences where the gauge flatlined when accelerating hard (2.8-3K rpm) from a stop as if it wasn't reading at all. During these instances, I would immediately back off the throttle and it would return to normal.
There is a noticeable ticking and given the mileage I would expect some wear to be part of the cause of a low pressure reading. I've also run some engine flush through it to help clean out any sludge in the oil pick-up screen. Looking through the archives, I've noted that replacing the oil sending unit seems to be a fairly common task for those with low pressure readings. Where exactly is this located and what is involved in replacing it? Several old posts state that it is near the oil filter, but the autozone web site states that it is located _inside_ the oil filter adapter. There is no reference to it at all in my Haynes manual. I'm also curious, is this unit simply a sensor for the gauges?
Aside from the sending unit, are there any other possible causes for these readings? I assume the pump is fine as the readings are normal to start. FWIW - I'm running Mobile One Syn 0W-40 and a Purolator Plus filter.
Thank You,
-Paul