Check if you have oil...

 

Did you put in enough oil? According to the manual, the 4.6L V8 Northstar requires 8 quarts (or 7.6 L) of engine oil. If you only put in a gallon, you run the risk of starving it of oil and mechanical damage can occur. Low temperatures and low engine speeds would worsen the situation to the point where the pressure drops and a warning message is sent.

If you have done all things correctly, one possibility is a bad or dirty oil pressure switch. These sometimes get fouled up and can be cleaned to prevent erratic operation.

 

Good advice.......a low enough motor oil level will trigger low oil pressure and the light. I think the psi threshhold that triggers the low oil pressure light on the V8 Northstar is 6 psi. And the OP had his oil changed, didn't do it himself. I trust no one to add back in the correct amount of motor oil, always check it myself after the car has sat on level ground for a while.

More than once I have found the level a half quart low which should never happen when the techs have the spec, use it, and they should be checking the level post change. OK, a half quart is not the end of the world. But.....

One time I had a motor oil change and within the hour I was 50 miles down the road on Interstate 80 on a 300 mile road trip to Detroit. I stopped for gas, checking the motor oil level too. I was 2 quarts low!!!! No, there was no leak from the oil filter or the drain plug. The tech just blew it, pure and simple. The reason does not matter.

I immediately called the place where I had the oil changed and let them have it. They offered me a free oil and filter change to appease me. "Why would I ever trust you again to work on my car when you can't get something so simple done correctly? I'm now going to go check the tire pressure you guys were supposed to check. " Then hung up. Yup, 2 psi lower on all 4 tires than I had requested. They were just as proficient (NOT) at that simple task too.

Lessons learned.

PJ

 

after letting it sit a while checked the oil level and it came up fine. I also started it up and let it idle a bit without DIC indication warning or oil light coming on.

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where is the sensor located so i can try cleaning it??? thanks for all the advice ;-)

 

It's on the oil filter adapter near the top, looks to be facing forward. Manual says to remove adapter to remove sensor. Need more?

 

@Glake89...any details would be great...i am definitely no mechanic. appreciate that. BTW...i checked the oil level again after it sat for a few hours and looks full...no oil leak visible either. i drove it around the block a few times and no warnings/lights/indications...i just hope it doesn't pop up on my way home!

 

Well, it's not easy to get to so if no more codes or trouble, maybe leave well enough alone. In the meantime, stop by a parts store and ask them to read your DTCs. Let us know what they are.

 

Well, i got home fine yesterday but today as i got to work, i stopped for gas and as soon as i put the car in park, the same warning came on. I shut the car off, got my gas, checked oil level and it was normal. Got back in...no warnings...got to my office no problem. Very frustrating but i'll check into the DTCs. Thanks again!

 

You have a pressure not a level problem, they are different.

You can still have good oil pressure with low oil level, ask the V6 guys.

So you need to see what's going on with your oil pressure, you have low oil pressure or the ECU thinks you have low oil pressure.

Can you get one of the those real time scan tools to monitor and/or log oil pressure? Now this will only tell you what the sensor sees, the only way to see oil pressure is with a gauge plumbed in but the scan will be a good start.

 

@Conedoctor: Thanks for the info. Was just checking levels as this was something i read about. Will definitely have to check the pressure out and see what's going on. it's just so frustrating when it comes and goes like that.

 

Do not drive the car. It has that warning for a reason. You will damage the bearings if you continue if you haven't already. There's a real the car is saying to shut it off.

 

Can't the oil pressure psi drop low enough to the threshold and trigger the low oil pressure light if the idle rpm is low enough.....yet not so low as to cause the engine to stumble or die? I am no mechanic either. Just wondering as I follow this thread.

PJ

 

I would not get too worried right now as the warning goes out and if you lost oil pressure you would know it, you may have a pump going bad and loosing pressure as flow slows down, you could also have a bad bearing killing your oil pressure and letting it all out.

Other thing would be a suction issue that resolves itself but usually a suction blockage gets worse if you increase the pump speed.

 

so far i've had no problem with noise or starting or anything with the engine...planning on checking the DTCs on my way home. really hope it's just a bad or dirty oil pressure sending unit.

 

Mine does the same thing. Had nothing but problems with gauges. Had gauge cluster replaced. Same problems. Ecm module codes when it rains. Security lock outs and key stuck in ignition. Traction control lights. Horrible and I'm told some of new ones have same issues so obviously never resolved

 

Interesting, I started getting that warning in 2019 about a month after buying my ‘09 N* with 71k miles on it. Scared da crap outta me. A Cadillac dealership had throughly checked the car out & except for the astronomical estimate to stop the infamous oil leak all was fine. The 1st time it happened the temperature was below 40 degrees. After a few minutes it stops. After winter the warning stopped until the day before we were about to begin a 2,000 mile trip in May 2020. We completed the trip without any issues & no warning again until the temp drops below 40 degrees during fall/winter. Took back to Cadillac & an independent mechanic shop and neither could produce any codes! Are these “phantom” warnings and/or electrical gremlins? Gretchen has 78,000 miles now & runs great….with the exception of the oil leak.

Humm, could the faulty gasket that’s causing the oil leak be the issue? Contracts when cold then expands when warmer and/or the engine warms.