218 Canadian engine , So I get the engine all back together after I replaced the rear main seal the oil pan gasket and installed the missing main bearing cap gaskets that the previous owner had neglected to install , started it and now I notice I have a fluctuation in the engine oil gauge , installed a second shop gauge into port #1 behind the generator, noticed that the gauge in both the truck and the temporary one fluctuates but never below 10psi then 2seconds later 20psi then 2seconds later 10psi and so on ,rev engine and I get 35psi ,changed oil pump with another know good spare one and same thing . I am running 5w-30 oil has anyone else got any suggestions,I will be dropping out the oil tomorrow when the parts store is open and will be putting 30w in hopping this is all that is wrong . I have provided a short video for you entertainment.
50932504280__A301233C-E744-4CF0-8B58-933CE594EC27.MOV