Cadillac Seville / Cadillac Eldorado Forum Discussion, Stop engine...low oil pressure in Past Cadillac Vehicle Discussion; So I got this warning on the DIC the other day 8/20/13. From the research, I found numerous instances of ...
So I got this warning on the DIC the other day 8/20/13. From the research, I found numerous instances of this happening with other posters BUT in every case they got the warning while driving. Well I get the warning as soon as the car is started. As soon as the "Monitored Systems OK" message goes off, Stop engine...low oil pressure comes on. Also, the car kinda sounds like a diesel.
Well, today 8/23 I got the engine oil pressure switch and promptly replaced it based on the advice that was doled out in the threads that I read. Started the car and the message immediately comes back... so I stopped the car. I double checked to ensure that the switch and connector was secure which they were. I started the car a second time...same thing. I tried it a third time, this time I gave it some gas while idling...message came on, car "dinged" but then the message went away. I then took a short drive of a few miles, and when I returned home I let it idle for 10-15 mins. it got good and hot but the message does not come back.
Can I definitely say that this issue is resolved?
Why did I get the warning again after changing the switch?
What happened when I gave it gas at idle?
There was also advice to overfill the oil by 8 quarts, would I need to do this?
low oil pressure with engine rattle means pressure relief valve was stuck open. reving motor usually fixes it. adding extra oil helps the process to unstick the relief valve. you said you heard top end rattle initially. is the motor idling quietly now? you oil pressure switch may have been ok. starting and stopping motor obviously changes oil pressure from zero to 30-40 psi. this pressure change can be enough to tweak relief valve.
Automobile(s): White Diamond '03 DHS (with floor shift)
Re: Stop engine...low oil pressure
It's actually a check valve. If it sticks open, the oil pump looses it's prime and the ONLY way to get it back again is to overfill the crankcase by 8 qts. That submerges the oil pump and re-primes it.
If you had top end noise at idle it was probably more than an indication problem (EOP switch).
Not sure why you got the message again after changing the switch, but revving the engine increases the RPM and thus the oil pump RPM and consequently the oil pressure.
I would cautiously consider it fixed while holding my breath for a while.
Took the car out today, plenty highway miles at 75mph and some city miles, numerous shut off and restart everything was good. So rather than hold my breath, I'd keep my fingers crossed that this episode has ended.