I have a 1990 C4 Convertible. The low oil lit is on in the DIC. The oil pressure and temp gauges are normal. Dip stick shows full. When I bought it the oil light had been removed. I went to two different Chevy dealers and asked for it's location. They both said it's on the side of the oil pan above the drain plug. The print out one of them also shows that to be the location. I noticed that the print said L5. I told the it's a L9. They told me it's in the same place. The oil pan in their print has ridges mine is smooth and my drain plug in the rear of the pan. If any one knows where it's at on this 1990 L98 engine it would be a great help.

Smooth Oil Pan with drain in the rear

Single wire sensor in the engine block above the oil pan forward of the starter motor.

Sensor above the oil filter

 

Welcome to the forum.

So are you saying that your oil pan has no threaded location for the oil level sensor? If not, then I suspect it's not the original oil pan.

 

I'm starting to think that. I was hoping someone wit a C4 would tell me that they changed theirs, as they are known to fail, and it was in a certain location. I'm getting a CAT Converter replaced tomorrow and will have it up on a lift. looking under it with a couple of jack stands it's difficult to see much. You would thin if the pan isn't original the connector wold be left hanging or a couple of wires dangling.

 

You ever figure this out I have the same issue can't find any wires in the oil pan doesn't have a spot for the oil level sensor

 

Welcome to the forum. Since this thread is over 2 years old, you might want to start a new thread with your question.

 

I never found it. When I bought the 90 Vette it had a after market radio init but had the original speakers. I put a double DIN touch screen radio with a back up camera in it's place. That is when I discovered several of the lamps in the DIC display were missing. The Low Oil lamp was one of them. The other was for the ABS System. That took me down a whole different rabbit hole. So I never did figure out if a previous owner changed the Oil Pan to one without the sensor or not. The next time I play with the radio I will pull the lamp so the Low Oil light will stay off like before. I also have the Air Bag indicator light on. I had pulled both crash sensors off sanded the frames lubed them, but didn't help. Finally figured the passenger side sensor was bad, tried to find a replacement. Turns out 1990 was different and the company that made them doesn't exist any more. I tried to use a sensor from a 1991, but the resistance is different then what the computer checks. Tried to fool it by adding a resistor inline to match 1990's, but failed. Thought maybe a unreported crash may have been logged in the computer,so I sent it out to get the data scrubbed. Took the steering wheel apart and fount that the clock spring wires had been severed. Repaired the damaged wires but the light is still on. I love the car so I will just live with it's issues and wait for inspiration on how to proceed.

 

ive discovered the oil level sensor didnt really come about until 91. some of the LATE 90 models may have gotten outfitted with it, but wasn't until 91

 

As far as the air bag light goes you need to take it to a dealer.
more than likely with the age of the car the little " emergency trigger" battery may be dead.
It's purpose is to fire the airbags in the event of a major crash that kills the battery before the airbags can deploy.
They are not user serviceable to my knowledge.