Flickering Oil Light

So I got my beast back last night; new battery, new front suspension bits, idler arm replace, leaking oil cooler fixed, wheel bearings tightened, left side downpipe flange replaced and new headlights.  Steering is much tighter now and now she's not galloping across the road, great!

So I was driving and everything was fine, I'm up to speeds about 50 MPH, but she's hesitant.  She's idling rough and wants to stall when stopped - this has been ongoing, still trying to get to the bottom of it - but at speed she's a workhorse.  

I've been driving for about 20 minutes, cars warmed up, I slow down to about 20 to take a turn and the oil light flickers and comes on.  So I pull over immediately, turn it off and pop the hood.  Looks like I'm down a little on oil, but still in operating range.  I put in 3/4 of a quart that I have in the back (it's a RMW BTW) and start her up. I hear a quick knock then nothing.  Running fine, oil level is in operating range - on the 3rd "dot" out of 4. But the oil light is on. I rev it slightly and it goes off.

I had to get home so I drive her home and while at speed there's no oil light. If I come to a stop or come close to a stop, it comes back on.  But if I shift to neutral it'll go off or if I give her a little gas it'll go off.  Checked the oil again when I got home, level is fine.  So now I'm worried, engine only has 105k on it.  

I've searched the forum and haven't seen this issue brought up, has anyone else experienced this?

The low oil sensor is on the side of the oil pan. Check the wiring.

Tom

Sounds like an oil pressure problem to me. I would guess the stalling when stopped is the pressure dropping enough that it shuts down the fuel pump. With that and the oil light coming on I would guess it is your problem.

Ok, so if I understand correctly, if the oil pressure drops enough the engine will shut itself down - is that correct? She was previously having this "near stall" issue before and the oil light didn't come on. I'm wondering if maybe the low oil sensor got knocked loose - but it wouldn't explain the light going off when I rev a little.

I had read on another forum that the throttle screw might need to be adjusted - that the car could just be idling too slowly.

The low oil sensor will not affect the gauge and pressure light. Depending on what engine you have, it could be a couple of different problems. First start with the oil pressure sensor on the side of the block above the filter. If that does not fix the pressure readout issue, check the pressure with a mechanical gauge. If the pressure is actually low, it could be either the pump relief valve, or the main bearings are worn/damaged.

The idle screw should not be adjusted. It is sealed for that reason. The stalling/poor idle is another issue.

Depending on the engine/car, the oil pressure-fuel pump pressure switch is an alternate path to power the fuel pump. The computer is the primary fuel pump circuit. If you have a 94-96, there may be a circuit that shuts down the engine if the oil pressure falls below a lower limit. I believe the TBI cars do not have that feature, because my LO3 would run when the pressure read 0 psi., and the light was on, as well as the chime dinging in my ear.

Guess I should have mentioned this is a 1994 RMW

You should replace the sensor first. It is probably located at the rear of the engine on an LT1. If that does not fix the issue, you either have a weak/broken relief valve spring in the pump, or the mains are worn. Another possibility is a ground fault. Check the grounds at the bottom of the A pillar on the driver's side.

You should check your codes for any issues with sensor for the idle issue. The idle screw is the one thing it is NOT the problem.

only proper way to check low oil pressure is to use a mechanical gauge,.

If your motor is running poorly and idling badly/ slowly, it will trigger the light,.

perhaps you need to correct the poor idle first,.

I have driven LT1's to their deaths a couple of times,. and even with very pronounced death rattling,. they didn't trigger the light at idle,.

Fred Kiehl wrote:

You should check your codes for any issues.

That would be my thought also. The codes pointed me to all kinds of sensors which solved non-specific engine stumbles.
And your oil sensors are about due anyway, if my car and other stories I've read on this forum are any clue.
Sensors are generally cheap and relatively easy to replace.
Might as well make sure the car is reading things correctly before you start messin' with more substantial changes, IMHO.

Pulled some codes (by the way, idled just perfectly while doing this)- just need to decipher them, I believe the 1 in front of the 3 digit number means it was a prior code that wasn't cleared, but for the most part these just do not correlate to anything I can find:

02-126 (history code I believe)
02-110 (history code I believe)
05-187 (program number I think)
13-73
16-124
17-126
19-199
26-56
29-19
30-100
34-128
35-128
36-10
38-05

I don't recognize that format either. Perhaps an LT1 owner who uses the same tool you are using will chime in here soon. That's a lot of codes, which is good if it gives you a lot of clues.

How did you pull the codes?

Those codes came out of the HVAC system and I have a feeling most of them are not "valid" because they don't correlate to the breakdown I found on the site of which codes mean what.

However, I think this has got to be an electrical issue at low engine speed. But we shall see. Unfortunately this also means my road trip with 4 friends will be taken in a rental Buick instead of the RMW, but I'd rather shell out the cash for a rental instead of shelling out the cash for an engine rebuild.

The paperclip trick does not work on 94s.

This is still OBD 1 right? OBD 2 didn't come online till '96, is that correct?

Alright, I'm about 90% positive what I have here is an electrical issue. I was driving her in my neighborhood to get her up to operating temp and try and trigger the oil pressure light so see if I actually heard any knocking or if it was just my imagination.

The dashboard christmas-treed during the drive, lights coming on, going off, flickering, fading in and out. But eventually they all went out (this was about 30 minutes.) I stopped, and the oil pressure light comes on, but no knocking, no noise. So I drive her a little bit more, the throttle response is kinda sluggish, but no noise from the engine. I park her, oil light comes back on. I listen. Nothing. Rev her a little, hear what could be an extremely faint knock or just how the engine sounds after 21 years.

So has anyone else run into this potential electrical boogaloo? I'm wondering now if I SHOULD just take her on that 300 mile round trip filled with people this weekend and cancel the rental.

why is the OP now called guest?

"She/her" has gotten creepy in this thread.[/quote] I laughed harder than I should have reading this....

phantom 309 wrote:

why is the OP now called guest?

OP deleted their account yesterday with no explanation given.

Don't know if they were offended at something that was said, or just didn't think this place was worth their time.

- J

It was the paperclip that did it,..

obd1.5. lol

atlantadan wrote:

Well that sucks. I was just poking him a little bit. Geez.. Sorry dude! Come back!

You shouldnt have called "her/she" creepy.

Her name wasn't Bruce, I mean Caitlyn Jenner was it? Sheesh the thing you miss when your away from the PC for a few weeks