Stop Engine Low Oil Presssure

erroneous · #1 (**permalink**) 07-05-05, 02:07 PM

My 1996 Deville had a flickering oil lamp at idle, with engine at operating temp.
Reading through these posts, I surmised that the culprit was a oil pressure switch.
I just had it replaced at the oil change centre with a oil change, and now its worse. The light flickers at all speeds when I am coasting, (no acceleration) and I, for the first time, just got the dreaded message above. The engine is not running hot (between 200 and 228 degrees) and not making any noise. But now I am even MORE concerned.
Any ideas what else this could be?

**Ranger** · #2 (**permalink**) 07-05-05, 04:53 PM

Did they use an OEM switch for the replacement? If not, that could be your problem.

daemart · #3 (**permalink**) 07-05-05, 05:42 PM

Okay, a few questions.
1. Where do you live and drive?
2. What kind and weight of oil are you using?
3. Are both of your radiator fans working?
4. Is your coolant level where it's supposed to be?
Get back to me.

Don

erroneous · #4 (**permalink**) 07-05-05, 11:03 PM

Thanks for replying guys
I used GM part# 12571721. Oil pressure switch.
I live in Northern NJ
Using castrol 10w/30w Synthetic
Havent checked the radiator fans
Coolant level was OK
Car gets driven about 3K per yr, garage kept and always dealer serviced EXCEPT for oil changes, Dealer is not convenient for oil changes
Thanks

N0DIH · #5 (**permalink**) 07-06-05, 03:03 AM

Stick a mechanical gauge on right away and do not drive until you verify the oil pressure is there or not. A NorthStar is a terrible engine to lose.....

daemart · #6 (**permalink**) 07-06-05, 12:19 PM

I don't think this has anything to do with your oil. It happens when your engine gets too hot and the oil thins out. This is sometimes a problem with multi-grade oils. After getting your oil this hot and this thin, I would change oil. Sorry. You need to check your cooling fans by disconnecting them where the wire plugs into them. Run a couple of small wires from your battery and touch them to the contacts built in to your fan holder (unless you've bought after-marlet fans, in which case there is a wire coming out with a plug at the end). If the fans turn, then check your relays.
There are three relays right behind the radiator. The one on the passenger side is for the fan on the passenger side and likewise for the relay and fan on the driver's side. The relay in the middle is for both. All three relays can be unplugged.
If you don't want to do this yourself, have a mechanic-type person do it for you. If you take your car to a mechanic, he will replace the fans and charge you whether they work or not. Come back to the forum and let us know what you did.

Don

erroneous · #7 (**permalink**) 07-06-05, 06:24 PM

So would my coolant temp go way up then, if the oil was cooking?

daemart · #8 (**permalink**) 07-06-05, 07:09 PM

Like I say, the engine is getting hot first, which in turn makes the oil hot and thin, which makes the pressure sensors not work. Anytime you get that STOP ENGINE message, it means that your coolant is too hot. Check your fans and we'll go from there. Later this evening, I'll have something on my website (daemart.com) showing how to check the fans.
Don

erroneous · #9 (**permalink**) 07-06-05, 11:07 PM

Thank you, later this weekend I will post my findings. I can test the fans but I dont wanna mess with the relays. My neighbor is good with that stuff.

**Ranger** · #10 (**permalink**) 07-06-05, 11:44 PM

If the light is flickering it may just be an intermittent connection. Check the connector for cleanliness and tightness.

soccer_eldorado · #11 (**permalink**) 07-07-05, 05:40 PM

Hey, I had the exact same problem on my 96 eldorado as you describe. Sal Collaziano recommended switching oil type to the Rotella 15w40 oil, cured the problem right away, hasn't happened since. I live in Miami, so its always hot and the light would always flicker. Seems to be a thing with 96 northstars, each year seems to have its own little quirks, and this is one of them. The day I changed the oil, the light flickered for a few days ( I thought I hadn't solved the problem) but after about three days, hasn't happened at all.

EcSTSatic · #12 (**permalink**) 07-07-05, 09:55 PM

Quote:

Originally Posted by erroneous

My 1996 Deville had a flickering oil lamp at idle, with engine at operating temp.
Reading through these posts, I surmised that the culprit was a oil pressure switch.
I just had it replaced at the oil change centre with a oil change, and now its worse. The light flickers at all speeds when I am coasting, (no acceleration) and I, for the first time, just got the dreaded message above. The engine is not running hot (between 200 and 228 degrees) and not making any noise. But now I am even MORE concerned.
Any ideas what else this could be?

So what happens when you put the old sensor back in? Does it get "better"? I had a similar problem in a TurboCoupe. I ended up replacing the new sensor with another one.

erroneous · #13 (**permalink**) 07-12-05, 05:08 PM

I checked out the radiator fans, they're working. I had to wind up bring the vehicle to the dealer because between work and family, I have very limited time for vehicle troubleshooting.
They just called me and suggested that they replace the oil pressure switch that I BOUGHT FROM THEM. When I reminded them that I just got it from them, they want to put another one in (free). If that doesnt do it, he said thay'll have to tear apart the motor to "find out' what the problem is. Sounds real expensive, I said. So my GM service tech suggests that i TRADE IT IN for a new one . Mind you, this car was owned since BRAND NEW by my father who always meticulously maintained the car. There is not a scratch, mark, etc anywhere and it's got 90K on it.
After all, he says, with a GM card, and employee pricing, I can get you in one for ONLY 37 large.
I am pretty pissed off with this. What kind of crap is this? We cant fix it so trade it in? I wouldnt consider buying any GM except a CAD anyway, but now I'm not so sure. I'll post tomorrow

**Ranger** · #14 (**permalink**) 07-12-05, 09:49 PM

And after you trade it, rest assured it'll be fixed and on the lot.

Anthony Cipriano · #15 (**permalink**) 07-13-05, 12:58 AM

Have them replace the oil pressure switch and check the connector. If the switch is fine and the connector is tight and the problem persists then I would consider simply using the 15W40 Rotella oil. The engine needs very little oil pressure at idle/low RPM (like when you lift off the throttle coasting) so it really isn't much of a concern if the engine is on the low side for oil pressure when at idle and hot. The slightly thicker oil will likely offset this tendency and eliminate the light flickering on.

The other possibility is the wiring harness leading to the low oil pressure warning switch has chafed or something and is grounding out the wire to the switch causing the light to flicker on.

One more thing. Have them check the torque on the damper bolt. The harmonic damper bolt clamps the oil pump drive on the crank snout. If , for some reason, the bolt has loosened it might be allowing the oil pump drive to slip. This is highly unlikely...but it is easy to check when the car is on a hoist to replace the low oil pressure switch.