1997 Buick Lesabre

Engine Performance problem
1997 Buick Lesabre 6 cyl Two Wheel Drive Automatic 145000 miles

when I start the car the oil light is on but when I put the car in drive and hit the accelerator the light goes off. Every time I stop at a stop light the light comes on and when the light turn green I hit the accelerator the light goes off. So what do you think the problem is, and where can I fine the area where the problem is located?
June 30, 2008.

Find the oil pressure switch remove it and hook up a mechanical gauge-if pressure is normal -replace the oil pressure switch if abnormal could be the oil pump, engine bearings, etc-

Jun 30, 2008.