Oil pressure problem?

[ecuastyle84]

I own a 91 e30 318i 4dr. Few days ago I notice the oil light was on under the cluster, at start up it doesn't come on but after running it for a few mins it comes on. I drive it and it goes away then comes back, so I replaced oil pressure sensor with a new one since it was the cheapest to start with. I also changed the oil with 10w-40(from what I read online alot of m42 owners are using, correct me if I'm wrong tho). I hear no knocking or any of that from the motor, it sounds healthy. I removed the oil cap and I see oil spitting around in there which tells me I have oil pressure no? Besides confirming if I have oil pressure with a pressure tester could it be possible that I may have an issue with the wiring? Or cluster?

[DesktopDave]

Did you check the upper oil pan bolts?!?  Don't drive the car if you haven't checked them!  The upper pan holds the gasket...and the main oil passage is cast into it, off the oil pump.  Problem is, the little bolts can loosen up over time.   If that happens, the upper pan drops slightly, the gasket slips out inside the block and you lose oil pressure (since it's now just pumping oil back into the crankcase).  Drain the oil, drop the pan, check the upper bolts that you can see.  The front ones are the critical ones.

Some of us have even found them in the oil pan.  My pickup had a mark from a bolt, but the bolts themselves were tight.  They're small bolts so don't overtighten them...I used a bit of blue locktite and tightened them to maybe 20 ft-lb?  Not tight at all.  They're still holding the last time I checked.

[ecuastyle84]

Did you check the upper oil pan bolts?!?  Don't drive the car if you haven't checked them!  The upper pan holds the gasket...and the main oil passage is cast into it, off the oil pump.  Problem is, the little bolts can loosen up over time.   If that happens, the upper pan drops slightly, the gasket slips out inside the block and you lose oil pressure (since it's now just pumping oil back into the crankcase).  Drain the oil, drop the pan, check the upper bolts that you can see.  The front ones are the critical ones.

Some of us have even found them in the oil pan.  My pickup had a mark from a bolt, but the bolts themselves were tight.  They're small bolts so don't overtighten them...I used a bit of blue locktite and tightened them to maybe 20 ft-lb?  Not tight at all.  They're still holding the last time I checked.

Ok I'll def check that cause I heard about those bolts coming loose over time

[ecuastyle84]

Did you check the upper oil pan bolts?!?  Don't drive the car if you haven't checked them!  The upper pan holds the gasket...and the main oil passage is cast into it, off the oil pump.  Problem is, the little bolts can loosen up over time.   If that happens, the upper pan drops slightly, the gasket slips out inside the block and you lose oil pressure (since it's now just pumping oil back into the crankcase).  Drain the oil, drop the pan, check the upper bolts that you can see.  The front ones are the critical ones.

Some of us have even found them in the oil pan.  My pickup had a mark from a bolt, but the bolts themselves were tight.  They're small bolts so don't overtighten them...I used a bit of blue locktite and tightened them to maybe 20 ft-lb?  Not tight at all.  They're still holding the last time I checked.

I checked those 6 bolts and none were loose.