Quote Originally Posted by dberens
its bouncing maybe 2-4psi, but a fast bounce. this is a new start up , no knocks ar bangs yet
There are a multitude of reasons why you could see minor pressure fluctuations including all of the above mentioned things. For starters a gear pump is by its very nature not entirely smooth. If you had a piezoelectric gage you could actually see the gear tooth frequency in the pump!

Your liquid (glycerin) filled gage is designed to dampen fluctuations though and 2-4 psi is even on the lower side of its resolution. That means I don't trust the gage to resolve 2 psi that well.

However one thing that you mention is that it is a fresh build. This could simply indicate that the rings are still seating and the fresh build blow by you are getting alone would readily account for the modulation of pressure you are seeing. As long as the pressure is not too low and comes up quickly to a steady value with engine speed I would not be overly concerned.

Kitz