2.5T Oil Pump Question???
 

My 850 Turbo valves rattle like crazy on the first start up of the day, then settle down and I have no more issues until the next cold start...as if all the oil in the top end of the motor drains back into the sump.

I know some engine oil pump designs have a spring loaded one-way valve that prevents this, can anyone help with this, or provide a different explaination of why the top end rattles so much on start?

Motor has 140K on it, with "minor" oil consumption ~ 1/2 Quart per 3,000 miles between changes if that helps anyone.

Thanks!

Jim