oil pressure low

[tonttu]

my car is firebird 3.1 v6. last summer i took my car and take it to get new paint.when i drove my car to the painters place my oil pressure was ok.like always before,in the last two years that i owned the car.so i left my car to the painters place.and my car was there about 5to6weeks.so when i went pick up my car,and start it, the engine was little bit strange to start.when i turn the key it was running couple seconds and then the engine turn off.so i started again and then it was running okay.i think it was little hard to start because it was there almost 6 weeks.but then i look at the oil pressure needle and it was at the minimum level my v6 oil pressure gauge dosnt have numbers just a about 5or6 white lines so my oil pressure is at the first white line so it shows minimum oil pressure its not the red area it has ever been there,it just the first white line at the oil pressure gauge and before,when i went and leave my car to the painters house oil level was almost at the maximum level.and now when i drive my car its always at the last white line.and when i tap the oil pressure gauge or close my car door,oil level needle goes up maybe one or two white lines.and when engine is cold,like it been outside one day and i start my car my oil pressure needle goes up even before i start my engine i just put the key to ignition and turn the key once so then of course,car dosnt start yet,there is just power on but even then oil pressure needle goes up and stays up when i star the car and let it running.but,if i turn my engine off like after 5or 10 minutes.oil pressure needle dosnt go up anymore if i just put the power on and when i start it.oil pressure needle just goes barely at the first white line that shows minimum oil pressure.so could my oil pressure sensor or sender unit be broken?and my car painter was also painting my engine room,so i think he has first been using water to clean it and then took the old paint off and painted again.and my engine room is also very dusty i nodest that when i first went and look all the places that painter were painted.so could it be that all the water or dust could been damage my oil pressure unit?and where is oil sensor and sender unit located in my 92 v6 3.1 firebird??and i also nodest that my car is leaking oil littlebit.could it coming from broken oil sensor unit or something?im very confused bottom of the line is that,i have that car about two years now,and my oil pressure has always been at the right position it almoust been showing maximum oil pressure.and after i took my car to be painted.and after that my oil pressure needle dosnt go as high,as it use to been.help please [img]graemlins/bowdown.gif[/img]