I have just finished my swap and I started the motor and only make 20 psi of oil pressure and the oil pressure won't go up much when I raise the rpm. So I read online that its mostly caused by the o ring for the pick up tube and changed that. And still didt fix the problem so I checked the front cover again the front galley plug was there. And then I thought it has to b the rear galley plug and I removed the transmission and found that the rear one is also there. I'm really frustrated now after wasting so much time. Please help me..... Do u think I should go back and change the blue o-ring to the red one for the trucks? ........the set up is a lq4 block with arp rod bolts new rings new bearings, ported l92 heads, fast 102/102......
I'm not sure on the bearing tolerance because I had some local builder put the block together for me but as far as the oil pump I first started it with one that was a ported stock oil pump and when I put the o ring for the second Time I did changed the o ring I used the oil pump that was on the car at the first place and that was doing 40-45 psi at idle I think that's a stock but not sure
a double road timing chain, if so the right [drivers side] oil pump spacer could have been install upside down, this will cause half the transfer oil hole from the oil pump to the oil galley to be blocked, cutting the effective oil pressure in half, or worth. i don't like to mention this other possibility, but is the rear galleries communication cover properly sealed. another one, the valley cover o rings  of them are they all in there? . Please let us know how you make out, David.
update: i checked the spacer on the oil pump and it was installed correctly. Then camster and i thought it might have been the fact that my injectors are too big and gets gas in the oil and it would thin the oil and make the pressure fall... but i changed the injectors back to the stock once and drained the oil and changed the filter and started the car and the oil pressure is still at 20 and 22 or so when i raise the rpm to about 2000. i changed the sensor also......please any ideas would help i dont know what else could cause the oil pressure to drop? you think it might be the block? maybe im not changing the o-ring right i did it twice and did't pinch it or nothing. ?????? please help
Sorry for the late reply so I just hooked up a mechanical oil pressure gauge and got the same reading and I was thinking since I'm getting oil to all of the rockers i should try a melling high volume pump give it one more shot with a new o-ring lol since its a lot easier doing that then pulling the motor out to check the bearings and all. I would be really upset with the guy that built the block for me if that is the case lol I really hope its the pump or oring I hope I did it wrong the first 2 times. Any other things you guys can think of please let me know. And thank you guys very much for the help at least I'm getting somewhere now.
Ok so I did the oring again and changed the spring in oil pump and got 35psi on the cold start and went down to 10 in about 40 sec or so ....I guess ill pull the motor next week and check the bearings and all that fun stuff .... Any other ideas or tips on Wat I should b looking for so I don't have to do this again lol ?
when your builder biult the engine he checked al the bearing clearences if he was worth half a ****. so you are good there. Unless you have reason to believe he just through new bearings at it and snapped it back up together with out checking? sounds like a oil pump problem to me.
__________________ 1979 camaro z28, 2004 built Lq4 swap(sold)
1983 Cutlass, LQ4/th400 swap soon to come and looking for sub 6 sec. 1/8 mile time slips..
He was not worth it lol it was the bearings that had too much clearance.after I took it out and measured it I called him to tell him and he told me to bring it by and I took it too him and a month later he still didt fix it so I just picked it up from him and did it myself and finally enjoying the car but still have some minor things I need to do . Thank you guys for all the help. Now I'm confused and not happy with the cam that same person grinded. Im just waiting to put it on the dyno and see if I need to do it or not.