low pressure occasionallty after new sensor installed

#1
like the post says , I was getting the low oil warning , I put a quart of lucas oil stabilizer and it cured it until I did research and seen the sensor was the issue. I installed a new ac delco sensor and new high milage oil. all was good for about 500 miles until I had to come to a short stop last night when the guy in front of me decided to stop at a green to yellow light. he must like to sit there and watch it turn red. welcome to nyc.

the engine stumbled and the pressure dropped dramatically bad sensor ? am I missing something ? also , is the sensor " bleed through " meaning does oil actually pass through it ? how does wet oil get on the contacts of the pigtail ?!?! yes I cleaned mine when I did the swap , but haven't looked at the contacts since
 
#2
If the engine RPM drops, the oil pressure will also drop because the oil pump is tied mechanically to the engine. The pressure sensor isn't actually a sensor but rather a switch. Below a particular PSI it flips, above it just basically sends a "all good" to the PCM, which then gives you a totally made-up reading on the gauge that may or may not be actually accurate.
 

MRRSM

Gold Supporter
#4
If you had to slam on the Brakes and the Throttle Body Butterfly momentarily slammed shut and got stuck or is in need of Good Cleaning... then your engine RPM might have dipped below 600 where your nominal Oil Pressure would ordinarily bottom out at around 12 PSI. Anything below 600 RPM ... and the Oil Pressure would drop low enough to cause a loss of the Oil cushion between the Crankshaft Main Babbitt Bearings... and the Crankshaft Journals... and a low metal on metal vibration would emanate throughout the Block until the Oil Pressure once again rose and “filled in the gaps” so to speak.