Post by
rustest86 »
https://forums.nicoclub.com/rustest86-u32079.html
Thu Apr 10, 2014 11:57 am
quickish back story, i recently rebuilt another S13 SR for my car, new oem bearings and oem S15 oil pump. since day one it had what id consider low oil pressure especially for a fresh motor, 16-13 psi warm idle but had 45-55 psi cold idle. well after 550 miles it wouldnt make over 3 psi @ warm idle and started knocking. i tore it back down and the #2,3,and 4 mains were torn past the copper and #3 rod almost spun. being cheapish i got some acl race bearings, some new arp rod bolts, and used another spare std. crank i had from another motor that had good oil pressure just blew a ringland. i probably should've replaced the oil pump too but i didnt. i did add a 3mm shim to it though. with 10w40 i still have lower than ideal oil pressure, infact at the moment i have 20w50 and lucas additive just to get 14psi @warm idle. i find it hard to believe that the pump is bad. warm oil pressure with 10w40 @ 3k is around 58 psi and climbs with the revs. with the 20w50 and lucas is 70 psi @3k. i honestly think its the relief valve but it moved freely in the bore. does anyone else know of another pressure regulator or anything else that would could cause the symptoms im having? im on the verge of ordering another pump but would be mad if i go though all that work and it does the same thing. as it is right now im not driving the car until i figure it out.