Weird thing driving home from work today, I looked down at the gauges on a 45 MPH road, and noticed the oil pressure light was flashing a steady on/off pattern. I knew the oil level was good, and the car felt totally fine driving. I pulled into a parking lot, shut the car off, waited a few seconds, then started it back up. No oil light. Drove the rest of the way home ~4 miles, with no further problems whatsoever. No oil light flashing, no weird sounds or smells or anything. I checked the oil tonight and it was right at the top hole as normal.

Some kind of fluke? Original engine and gearbox with 359,000 miles. Mobil1 0w-30 and STP oil filter every 6K miles as I've done for the past 10+ years.

I know for a fact that the oil pressure light has a connection to the ICU behind the under-dash fusebox, and I've had issues with that in the past, and have tried swapping it out for another used unit. Maybe that's the issue.

 

Cross your fingers it isn't an oil pump on the way out. Last time this happened, I removed the oil pump and the inner "metal gear" (whatever it's called) was in pieces. It happened after the 2nd pass on the drag strip.

 

Confirm oil pressure with a remote gauge. It'll tell you if it's just the oil pressure switch on its way out. At that mileage however, I wouldn't be surprised if the oil pump is on its way out, if it is original of course.

 

If I changed the oil pump I would have done it when I had the engine pulled out several years ago to replace the clutch, timing belt, oil pan gasket and a bunch of other stuff all at the same time. But honestly I can't remember at this point if I replaced it or not.

 

I would just confirm pressure then. Also looks like you can rent one from the local auto parts store.

Best Oil Pressure Tester Parts for Cars, Trucks & SUVs

 

According to the Helms, a flashing oil light means there was loss of pressure only momentarily and then it came back again. And if that's the case I'm pretty sure a gauge will show the pressure as perfectly normal.

 

Will the oil light flash or light up if there is a bad connection at the sensor? Did the connection at the sensor plug look good?

 

Haven't checked it yet. Might try to get it up on ramps this weekend to have a looksie.

 

A gauge would show you the fluctuations if it truly is. My suggestion was to use it as a way to confirm if your oil pump was functioning properly and pin-point the issue towards the switch or electrical system being at fault.