Hello im a proud owner of a 93 Z28 which I baby this car......Well recently i've noticed that when I get it below 1000 rpms im guessing around 700 to 600 the gauge will jump well over the 80 mark for a split second. So, im left with a somewhat noobie question should I be worried? The engine isnt making any noise and it seems to run great still. Just wondering if maybe my oil pump may be going out or if its even instrumental problems. Also the car has 104,000 miles on it im running Castrol 10w-30 should I change weight? because of the weather change? If that is an issue.

 

If it's only at a low RPM I would say you probably don't have too much to worry about. It's possible there is some air bubbles in the line and that's throwing off the sending unit, or the sending unit is going bad.