87 Fleetwood (RWD) Oil Pressure
 

My oli pressure light came on. I checked to oil level and I was a qt low but the light is still on. How do I tell if it is the oil pump or the oil sending unit or something else?

oil pressure
 

You need an oil pressure guage to check the pressure. Disconnect the blue wire at oil pressure switch,if lamp goes out the switch is shorted or engine has low pressure. You might want to check printed circuit connector for proper connection and oil pressure switch connector. Could also be faulty printed circuit.

did you fill it properly?
also, what brand oil filter are you using?






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Yeah I know I filled the oil properly and I am using a Fram oil filter. I just went and bought a Prestone filter and I am going to try changing the oil first and see if that works. If not I'll check the pressure switch.

Thanks for the input. I'll let you know what happens.

Others may argue, but I firmly believe in using only AC/Delco oil filters on my GM products. I still have a bad taste in my mouth from the engine that seized up on my mother after she had the oil changed on the '76 Coupe D-evil at a local repair shop back home(in the '70s). They used a Fram filter...car didn't make it two blocks before the engine locked down(there were NO issues with the engine before that point. The car was fairly new at the time). Upon disassembly, it was obvious the oil filter was completely blocked...no flow at all. Since then, and after learning a thing or two over the years, I've NEVER installed anything but an AC filter on a GM vehicle of mine. Call it paranoia if you will, but I haven't had an oil related failure with an AC filter.
I did try a WIX filter on my '82 Eldo once, because that was the only one they had...then that car caught fire and burned to the ground, so I don't know if the filter would have been an issue or not.

Does your light stay on all the time?
Does the engine "rattle" at idle?
Most likely, the wire for the sender is grounded somewhere, or the sender is bad. Installing a mechanical pressure gauge temporarily will tell the tale for sure. An engine only needs 10 psi for every 1000 rpms to survive, tho more is better, to a point.

oi pressure on 87 brougham
 

I have an 87 Cadillac Brougham. It has always ran great! Today I was driving up to big bear CA, going up on a big hill so I shifted to 3rd. Once I got up top I put it back on N and let it coast... I somehow forgot I had it on Neutral and I pushed on the gas as I approached another hill, once I realized I wasn't accelerating and that I had it on Neutral, I quickly shifted to 3rd. Bad mistake. My oil pressure light came on and my car shut off. I pulled over, check the oil level and it was now low 1.5 qts, I added oil, let the car sit for about 1.5 hrs, I got it to start but when it idles the engine rattles, when I press on the gas the pressure light goes off and it seems as if the rattle goes away but then it comes back. A buddy said that most likely I blew the oil sensor when I quickly shifted from N to 3rd as soon as the oil pressure light came on without easing off the gas first. I cannot believe I did that and I am embarrassed . ... Do you guys think it is just the oil pressure sensor?