That's my thought as well, but it would seem that a spun bearing would cause higher pressure.

I did clean the relief valve when I had the oil pump apart. I don't see how the valve could be fine on initial startup, but then stick open - unless the thinning viscosity as heat builds causes the drop.

I'm wondering about all the assembly lube I packed in the pump - and if that could cause the valve to stick.

Short of removing the oil pan and replacing the pump or valve, I don't know what I can do about it. Maybe an oil change will help.

I've never seen this before. <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

Frank