Acceptable oil pressure buildup delay

It some time takes a few seconds for the oil pressure to build up. I rebuilt the oil pump a few months ago and it was faster to build pressure in the beginning. Oil filter and oil has only run like 2 months. I didn't have an oil pressure gauge permanently installed directly after the rebuild, but the oil pressure switch certainly triggered faster. The buildup time also varies. Today it took maybe 3-4 seconds (but felt like an eternity) at one instance. Now I have a gauge. Both the gauge and the indicator light give consistent reads so it is unlikely to be a sensor problem.

Pressure after prime otherwise seems fine. Around 4 bars (60 psi) when cold and 1 bar (15 psi) when hot. When turning the engine off at 4 bars the system still holds pressure for a few seconds. Pressure increases with rpm and seems to top out at around 4 bars, guess that might be the setting of the relief valve.

Should I be worried?

 

There are reports here of the more recent Wix oil filters leaking back down and causing this kind of delayed oil pressure at start.

 

The small-diameter oil gauge tubing will restrict pressure as delivered to the gauge especially with cold oil. The longer the tubing used, the slower the gauge reacts. Not uncommon for the gauge to react slowly especially in winter.

But since it's not winter, my first guess is oil-filter issues. Fortunately, that's neither difficult nor especially expensive to test. Get a new name-brand filter that's NOT MADE IN CHINA, or built to be the lowest-priced filter on the shelf at the store, and see if things change when it's installed.

Wix filters used to be my standard. Recently, they've offshored some but not all production to Russia, Poland, China. There's no telling who is making the filters for Wix until you look on the filter.

The folks who own Wix (Mann + Hummel) also own Purolator. The Purolator filter for my BBC plow-truck, at my local home-improvement store was made in USA. Go figure.

 

More importantly, do you hear the lifters clattering or the mains knocking upon start up?
If not, don’t worry then.
There’s enough of an oil film on the bearings to support everything for awhile till pressure builds.
Back when one of my pressed on galley plugs blew out while driving and my pressure dropped to zero, I had the GS flat bedded home, BUT I started it up and idled into the garage, no noises whatsoever.

 

FWIW my boat has both electric & mechanical oil pressure gauges. Im using fat 3/16 line about 18 feet for the oil pressure....... The electric gauge literally registers instantly...... The mechanical depending ambient air temp..... A loooooooong time..