Volkswagen Repair: Golf 3 1995 GS Oil Light, oil pressure switch, low oil pressure

Question
Im quite educated when it comes to car enjins and i fix everything myself but this is a problem that i cant seem to figure out. I have a 95Golf3 1800 euro model and my oil light goes on at low rpm and the moment i take my foot of the excalarator or when i floor it then it goes of. I know it is oil presure but it seems that the oil makes its way to the top of my enjin. I thought it can be the sensors but there is two of them and i took the one of but the oil light still shows when i putt the ignition on. I took the other one of and the oil light dissapeard but after a while it came on again. The one is black( Aftermarket parts) and the other one is white. I just want to know if it is my pump or the sensor. Thank you very much for having a site like this because it helps more than you think. Thank you

Answer
Hi William;
The oil light may be coming on due to a perceived low oil pressure problem.  The oil pressure switch itself may be the culprit, but more than likely it's a combination of a couple of things.  I think your engine has some carbon deposits in the oil pan that are hard little chunks of carbon from overheated broken down oil that I refer to as "coffee grounds" because that is what they look like.  They cover the screen that protects the oil pump, and reduce the area that oil can be siphoned from, and since they reduce the area, they reduce the available quantity of oil the pump can get.  At idle it's significant because the oil pump is running slowly, and doesn't have much suction at that speed.  That's pretty much it.  If you take the oil pan off, clean it out, and clean off the pickup screen too, there won't be a problem with the oil light again...as long as you keep your oil clean, and filter clean.
There are 2 sensors because one is dedicated to the ECM, and one is for the instrument cluster.
The oil pump is working just fine, William, just clean out the pan, and the screen, or just start changing the oil a lot...like every 150, to 200 miles until it comes out as clean as it went in.  Oil is cheap.  Or, take the pan off like I said earlier.