Just in the last couple of weeks I have noticed that upon a cold startup it takes several seconds for ANY oil pressure to registar on the gage. As soon as it does, it always remains above 2 bar and 3 at anything above idle. This is on my 1985 500SEC with 115k miles. I know it is not a gage problem sice I had my wife start the car while I watched the camshaft oiler tube through the removed filler cap. Sure enough it took about 6 seconds to see oil. The car is now in the garage until I find the problem. My research suggests that the oil filter housing is draining empty as the car sits and therefor must be filled up by the oil pump first before I get any oil to the engine. I pulled the oil filter housing assembly off the block and see the little spring loaded check valve in there. Can this little sucker be bad? Can I get new parts for it? Could anything else cause such a prolonged delay in oilpressure buildup?...collapsed lifters? ...bad oil pump? ...Any ideas? Thanks, Brant