... happens until the car overheats or seizes up. If you're lucky, it is the pressure switch. If not, it's quite possible you've done some damage that might not be immediately noticeable, but will show up sooner or later. If it's not the pressure switch, have an oil analysis done (search the internet for this service) on the oil that's in the engine now to see what you've damaged (the analysis folks can generally tell this). Coming home this evening, my oil pressure indicator light came on. Hearing no expensive noises and with just a few miles to go, I made it home safely. I found the engine oil a quart low, so I added a quart. Cranked up, and the light went out for a few seconds, then came back on. I just finished reading the Bentley manual section, and plan to check the pressure sending switch. The photo of the 528e in the manual was not too clear, is the switch accessed from above the oil filter location, or below it?