Found out recently that while driving my R33 around, the oil gauge seem to be running slightly below the second bar. Normally it used to be staying around the middle bar ( bar showing 4 ). When I first start the car, it will be around the the highest bar which indicate 8, but after driving a while it will stay around the middle bar however now it is falling below the second bar. This happened after the first car service. I am due to second car service in 2 weeks time.
I have checked and I am sure that there are enough engine oil.
What could be wrong? Something wrong with the pressure?
Would appreciate any help I can get from anyone.
Thanks