gingerdom18

hi im haveing a lot of oil presure problems with my fiesta cosworth

had engine in and out 3 times

1st time oil presure gauge was reading 40psi on hot or cold idle and at any revs. so as 40 psi on hot idle is very good i was convinced that the gauge was just sticking at 40, un till the bottom end started knocking after only 100 miles

2nd engine was bought purely for the crank and a rod and spares as it had a melted piston and i also bought a new burton power HP oil pump etc BUT the crank was suposed to be orignal size and perfect but was -.75 grind and not 100% perfect so not wanting to use this in my good engine i changed the piston and put in new shells etc and put it in (different oil pump to the 1st engine and also diff head, block, sump, pick up pipe etc) and the engine did run spot on but still low oil presure. sames as b4 but ony 35psi at all times

i fitted a new oil presure gauge when changeing the engine 2. now have both mecanical and electronic gauges. both give ruffly the same reading

after this i was thinking it must off been 2 poor pumps and was kicking my self for not just putting in the new burton power one in the bodge up engine

3rd engine. back to the orignal block and head but a perfect crank and new burton power oil pump etc. and the oil presure is worse than it was on the old pumps. now im geting 40psi cold idle and 20 hot idle and the worse bit is that when reved it drops my 10 psi! as im sure you are all aware oil presure on these engine should be around 30psi idle and with a small rev shoot u to 70/80 psi

i have now tryed

removing the mocal oil cooler kit (incase blocked)
changed the standerd water / oil cooler (incase blocked)
changed oil filter and oil type

all were fine and made no diffrence

then thought about the oil feed to turbo restrictor hole size
and it didnt have one. i was sure that this was finaly the problem as it had a 6.5mm hole and should be 1mm but this made no diffrence at all
so im now all out of ideas after many months of problem solveing

any help would be much appreicated

cheers