700 SCI engine coming out
 

Still can't find low oil pressure cause,engine coming out to check oil pump or whatever.50 hours on Smartcraft, bummer.

700 sci low oil pressure mystery solved!
 

Mechanic found a floating plastic disc about the diameter of a quarter in the remote oil filter housing base.It would intermittently act as a flapper cutting off the oil pressure. Mystery as to how this foreign object got in the oil galleys.Disc is about 30/thousandths thick and tan in color.

I know exactly how it got their. Had the same problem. Just didnt think it would happen twice. Because the oil filters are mounted upside down, mechanics usually take an ice pick or screw driver and punch a hole in the top of the oil filter to let the oil drain down from the filter and not make such a mess when the filter is removed. If the person punches it in the middle of the filter that small disk can come come out of the bypass valve on the oil filter and falls down into the nipple the filter screws onto, and its a perfect fit inside the nipple. If they dont notice it and screw the new filter on the nipple, that disk will stop the oil from coming out of the new filter. Good news is, their is a bypass system built into the filter base in the event of a blocked oil filter.
Hope everything is ok....sorry I didnt bring it up before, just couldnt imagine someone had the same bad luck as me.

Ha beak,,,, good point,,,, im the engine builder who found it,,,, Ive asked merc , in service school, how to drain oil out of filter.... the answer was jab a hole in top of filter...which i dont agree with .....for many reasons ....glad we found the problem for the customer.......
Danny C

sounds like it's the anti drain back valve