Oil pressure on start up; losing prime?

[DylOrr]

I have a buddies truck I swapped a built motor in. I built the truck it was in previously and it didn’t have this issue, but it did sit for about a year before my buddy bought it. If it sits more than ~3 hours it takes 5-10 seconds to build oil pressure on start up, it even tripped the low pressure light briefly once. You can hear the motor chattering til it gets pressure. I know there’s a relief in the pump, 2 in the cooler, and one in the front cover. I hate to go throwing parts at it. Has anyone had this issue or dealt with it and know of a solution. It’s 15w40 and I already tried swapping out the filter. Thanks

 

[Chevy1925]

my old engine did that for years. every morning it would take a bit to bring pressure up. sometimes trip the light, sometimes not. always figured it was due to the engine oil cooler i had and old factory oil pump. the bearings all looked great inside. did that for 8 years.

only thing id suggest is pulling the oil pan and front cover to check for any loose/bad gaskets on the oil pump pickup. or maybe a spun oil pump gear.

 

[DylOrr]

my old engine did that for years. every morning it would take a bit to bring pressure up. sometimes trip the light, sometimes not. always figured it was due to the engine oil cooler i had and old factory oil pump. the bearings all looked great inside. did that for 8 years.

only thing id suggest is pulling the oil pan and front cover to check for any loose/bad gaskets on the oil pump pickup. or maybe a spun oil pump gear.

That’s what I was figuring. More of one of those tear into it things. I just really don’t wanna yank the motor I literally just put in :roflmao: