: Stop Engine Low Oil Presssure



erroneous
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? :banghead:

Ranger
07-05-05, 04:53 PM
Did they use an OEM switch for the replacement? If not, that could be your problem.

daemart
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
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
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
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
07-06-05, 06:24 PM
So would my coolant temp go way up then, if the oil was cooking?

daemart
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
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
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
07-07-05, 05:40 PM
Hey, I had the exact same problem on my 96 eldorado as you describe. Bobynski 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
07-07-05, 09:55 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? :banghead:

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
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
07-12-05, 09:49 PM
And after you trade it, rest assured it'll be fixed and on the lot.

Anthony Cipriano
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.

erroneous
07-13-05, 04:33 PM
[QUOTE=Anthony Cipriano]"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."

Thanks for the replies, really much appreciated.
The dealer replaced the oil pressure switch with another new one, and replaced the 8 qts of fresh synthetic oil I just put in and the problem has disappeared. According to my service advisor, we shouldnt be putting synthetic oil in these vehicles because it is "too thin".
So all I have to pay for is the 1hr or 2 of "troubleshooting".... This opens the Pandoras Box of traditional or synthetic oils? I always was led to beleive that synthetic was better?

EcSTSatic
07-13-05, 04:58 PM
The dealer replaced the oil pressure switch with another new one, and replaced the 8 qts of fresh synthetic oil I just put in and the problem has disappeared. According to my service advisor, we shouldnt be putting synthetic oil in these vehicles because it is "too thin".
So all I have to pay for is the 1hr or 2 of "troubleshooting".... This opens the Pandoras Box of traditional or synthetic oils? I always was led to beleive that synthetic was better?

Now you don't know if it was a bad sensor or the oil.http://cadillacforums.com/forums/images/smilies/hmmm.gif
There's nothing wrong with synthetic oil. You may have enough wear/clearance to cause pressure problems. The only way to know for sure now is to put synthetic back in.

Anthony Cipriano
07-14-05, 12:38 AM
If you search the forum using "synthetic oil" you can read all you want.

The engine is spec'd for conventional oil so I would recommend it. There is really nothing to gain with the synthetic oil so just use the conventional oil and drive it.

If it crops up again switch to the 15W40 Rotella/Delo/Delvac style of oil. More antiwear agents in the oil and slightly higher viscosity. I would recommend the 15W40 Delvac over any "synthetic" any day if you are looking for more basic engine protection.

erroneous
07-14-05, 06:16 PM
Same problem AGAIN driving home from dealer. Tech says engine may have spun a bearing. I really dont know what that means, but he is telling me that an extended warrantee will be cheaper than a motor. I am very frustrated. I am going to tyr the rotalla oil, otherwise I am at my wits end.

erroneous
07-14-05, 09:25 PM
Hey, I had the exact same problem on my 96 eldorado as you describe. Bobynski 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.


Were you also getting the message? It really freaks you out........Thinking your car is about to melt.....:want:

dkozloski
07-14-05, 11:33 PM
If your motor has spun a bearing it will hammer like a broken washing machine.

Try the Rotella oil.

Anthony Cipriano
07-15-05, 02:10 AM
Yea, try the heavier oil. Not sure why your engine is at the low end of oil pressure at low RPM but it really shouldn't hurt anything and if you had NO oil pressure you would know it.

If the engine is quiet then there is no way it has spun any bearings - besides, lower end problems or bearing problems are exceedingly rare in the Northstar engine - so rare as to be almost non-existent.

N0DIH
07-15-05, 09:28 AM
If you have any fuel economy concerns, I have seen no loss of fuel economy in my 94 FWB LT1 by running the 15W40 over 5W30 in mainly city/highway driving (basically stop and go driving only getting up to highway speeds between stops, I live out in the farm town boonies of SE Wisconsin, commuting to Chicago Suburbs daily, ~600 miles a week). Granted, my engine has now 160K miles, is very solid sounding bottom end. With 3.42 gears I get around 18.5-18.9 mpg average.

I put around 3-4K miles on the 5W30 then switched to 15W40 Delvac and have run around 5-6K on the Delvac with no significant fuel economy loss. And so far, still just waiting for the Oil Life Monitor light to come on, as per BBob, trust it....

raymondk
07-16-05, 12:04 AM
Check the oil pressure with a gauge.

erroneous
07-19-05, 05:30 PM
I brought this issue to a trusted mechanic recommended by a co-worker. He went to high school with him, and he works on all his families vehicles, has dome motor swaps etc and always does right by them. My co-worker is also somewhat of a gearhead himself, and if he trusts him, it's good by me.
He told me that he put a mechanical guage on the vehicle and at 3500rpm the guage is reading 40 psi.. About 5 psi idling...The message appears theoretically if the oil light comes on steadily for so-many (not sure?) seconds? So the motor is definitely pumping oil. He said also that he's been driving the car around in frequent stop and go traffic (and it's been over 90 outside yesterday and today) and not seen the problem other than a flicker here and there......
He also recommended going to a 10/40w oil as 90k on motor..
SLightly cheaper than dealer recommendation of pulling the motor... I am shocked that they would recommend this AFTER I told them that this car has MUCH sentimental value to me. I guess I shouldnt have told them that.
I hate to say this, but shame on you Mr Cadillac Dealer. You just lost a customer, and all my faith in Mr Goodwrench too. Last dollar i spend there.

dkozloski
07-19-05, 06:08 PM
15W-40 Rotella is the answer.

Anthony Cipriano
07-20-05, 01:08 AM
That pressure sounds perfectly fine.

If it is staying at 5 PSI the light should not be coming on.

I still wonder about the source of the oil pressure warning switches installed. An OEM switch is set at about 3 PSI for the light so it should never be turning on the light.

erroneous
07-21-05, 10:15 AM
I really appreciate all the information you all have provided. I must say this has been the most well maintained and informed forums I have ever visited. You guys are great, hopefully this will benefit others as well.
Not saying that I wont be visiting regularly anymore!
Cheers

erroneous
07-26-05, 10:00 PM
OK, on Friday,
After getting the car back from my friends mechanic, I noticed that damn little red aladdins lamp oil light flicker a few times. He filled the motor with 10/40w but he was unable to get the rotella oil. That day was about 95 degrees out.
Today was 100 degrees out. The cars coolant temp went to 235 while idling, (dropping off carpooler), after driving up the mountain road I live off of. Damn light comes on again. No dreaded message because I slightly kept the gas on. It always seems to happen right after the coolant goes over 225 or so.
And then by the time I got home, the coolant was around 212-215. I left it idle for 5 mins with the AC on, and then off for 5 mins and the light wasnt coming on until I backed into the garage. About same or slightly higher coolant temp. It went off the second I put it in park.
I can see oil pumping around the valves rocker arms cam etc so oil is definitely getting circulated.
Is there anything else I am missing? Is it those coolant temps that causing the oil to thin out as bobyinski and daemart mentioned? Are those coolant temps high? I really dont know....
I also noticed that the temperature spikes quickly under low speed load (like driving up the montain) and also comes down quickly too when the radiator is given more air flow (driving faster)..
I also appreciate your patience for what might appear to be ignorant questions, but my knowledge of cars ended around 1988 or so.... therefore understanding the n* to me is like trying to diagnose a computer with a mortar and pestle...blindfolded.... riding a unicyle....:drinker

erroneous
07-26-05, 10:02 PM
Oh, I forgot, is there something like an oil pickup screen or something else that could "clog up", restricting the flow while the motor is hot?

erroneous
07-27-05, 07:49 AM
And, sorry for the pps... I read something on here (it was an Aurora's N* with same problem as mine) about an "oil pressure sending unit" which I assume is different than the oil pressure switch I had replaced?

Ranger
07-27-05, 11:44 AM
Oh, I forgot, is there something like an oil pickup screen or something else that could "clog up", restricting the flow while the motor is hot?
Not too likely unless your oil hasn't been changed in 40K in which case you have bigger fish to fry.

dkozloski
07-27-05, 03:06 PM
Why keep fighting the solution? Rotella 15W-40 is available at most of the box stores like WalMart and Sam's. It's like dealing with a rebellious teenager that is going to try everything else in the world first before doing what works. That being said, watch him try it and it makes no difference.

erroneous
07-27-05, 04:18 PM
Hey did I just get yelled at? I think that’s the first time I felt like a teenager SINCE I WAS A teenager! :) =-) Really, I’m not trying to avoid the rotella oil…. The guy who worked on the vehicle said he could not readily get any. I’m not sure if it was time constraints, or too busy, etc.. Therefore, I WILL call around to find it and I AM going on my way home tomorrow to get this oil and will drain/refill it this weekend. I’ll drive my beater pickup in the meanwhile until this task has been completed. I would eagerly do it this evening, but can’t due to family obligations. (Cant leave small children alone in the house for 5 MINUTES…. INVITING DISASTER…. Mushroom clouds appear on the horizon , blood freely flowing, paramedics….’copters …. Etc:bighead:

Don’t get me wrong I take your recommendations very seriously otherwise I wouldn’t be here…

dkozloski
07-27-05, 04:49 PM
I'm not trying to yell at you it's just that the way the thread has developed seems humerous to me. I'm looking at it from a very narrow perspective. Here in Fairbanks, Alaska it seems like every time I look at motor oil displayed for sale, Rotella is included. I bet if I went out the door to buy some I'd drive 25 miles to every store in town trying to find it after shooting off my mouth. Good luck! I hope it does the trick. If not there is always 300W steam cylinder oil which is about the heaviest stuff I have ever seen. It approaches asphalt.

erroneous
07-27-05, 11:22 PM
I do remember putting in 3 qts 10/40 and 2 qts straight 50 mycle oil to get a 1977 fleetwood to stop knocking so bad it would wake my dad up when I would get home @3:00am at the glorious age if 18 yrs of age HEHEHE.

Seriously i will get the rotella and then I guess i'll really know.... pray for me I cant afford a car payment...... mortgage taxes children...etc etc no room :tisk:right now....

erroneous
08-02-05, 08:11 AM
OK... Drained the 10/40 the mechanic put in there. I let it drain for 3 hrs or so before refilling it.
I also for the hell of it bought some premixed prestone premixed dexcool (bottle says 50/dex/50 water and was suprised to see that the coolant tank took about 1/2 of it. I filled it to about 2" below the cap. I didnt "look" low.
So far so good. I put about 40 miles on it purposely driving up and down the mountain. No oil lamp yet. Today is supposed to be hotter, I'll have to see what happens later. I appreciate all your guys help, and will repost after a couple hundred miles.
I also saw other oils, 1 I remember called DELVAC, these oils also also labeled "heavy duty"... the rotella was the only one that said it was also appropriate for "cars"... the other ones said they were for commercial diesels .... Any comments? Is rotella the only one I should look for?
Thanks again..

Ranger
08-02-05, 12:22 PM
Rotella is the one that has been recommended.

TomS
08-03-05, 11:29 AM
Please keep posting as you figure this out. I have the same problem and I'm waiting to see what happens with your "fixes". Reading all of these posts I haven't seen anybody post the actual oil pressure reading. Have you or the dealer checked it? What should it be if I have mine checked?

erroneous
08-03-05, 01:46 PM
Update......
The rotella is definitely helping this situation.... yesterday was hotter, and I did get ONE flicker from the oil light as I stopped at the top of the mountain.. but it didnt STAY on.
I do recall earlier in this thread someone saying they lived in FL and it was always hot, and the light would always flicker at idle... The change to Rotella cured the problem after a few days... and a few more flickers....
As far as the ACTUAL pressure my car had, read earlier in this thread, I know i put it in here ....

erroneous
08-04-05, 10:33 PM
Update
I drove home the long way today (102 degrees out) and avoided going up the mountain (if you go around its not NEARLY as steep).
When I got off the highway, all the rest of the way home (stop and go traffic) my coolant temp did not go higher than 212 degrees!! And the oil light did not come on at all. So it seems that the oil light ONLY goes on when the coolant temp goes to 234 or so and then starts climbing back down again. (which is what happens when driving UP the mountain).
So what do I do? Just not drive up the mountain?
One again thanks for the rotella "cure" it seems to have helped enormously