took car to track last night. but this morning when I started it the oil pressure gauge read 20 at a cold idle i let it warm up and the pressure feel to 10 at idle. the car has yet to tap. I have already changed the gauge twice to make sure. The guage moves with rpm 10psi idle 20psi 2000 rpm 30psi 3000rpm....etc what could be wrong car just had a brand new oil pump put with less then 100 miles on it.