I have a 1993 AUDI 90 V6 automatic front wheel drive with AHH engine. After I replaced the timing belt and took a test drive the oil pressure light came on when the engine hit 2100 RPMs. As soon as the transmission shifts downward and the RPM drop below 2100 the light goes off. I have replaced both pressure switches and checked the oil pressure per manual. Oil pressure within range (5.8 bar) on switch B at 2000 RPMs. At operating temperature engine runs smoothly. No knocking noises at idle. Does anyone have any idea what would cause light to come on above 2100 RPM?