Hi, I am detailing my aunts 94 z28 and changing oil etc.. I have noticed that when revving the engine the oil pressure jumps. Is this normal? it doesn't go too high but i have not seen many oil pressure gauges but rather temperature. Also, i have the muffler off to replace and was wondering if it is bad for anything with out the backpressure. these are just questions i couldn't find when searching. Thanks for any help, Jason

 

The oil pressure normally incrases as the RPM go up. It will continue to increase until a preset limit is reached, at which time the relief valve will open and prevent further increase. The loss of back pressure will not hurt the car, but running with no muffler may hurt your hearing.