No oil pressure

[Ls1wrx]

I swapped an ls1 out of 2000 camaro with 99k miles into my 02 Subaru wrx and finally started it up, only to find out I didn't have oil pressure. Im guessing the motor has sat for maybe a year, just because the gas that was in the fuel line smelled bad. I took a valve cover off, and there was some oil pooled there...it was dry when I changed the gaskets awhile back. I took the oil pump out and it had oil in it, and the relief valve piston wasn't sticking. I had a spare pick up tube laying around so I slipped it into the oil pump with the old o ring and it slide right in with no resistance but looked like it would have sealed just fine. The o ring is oval shaped, but not damaged. Other than that, I dont see anything that could possibly be causing the problem. It also still has that galley plug in the front. Its just not getting any oil to the oil pressure port in the back. I was going to install a mechanical gauge and thats when I noticed it wasn't even getting any there. And I dont see any reason it would be missing the dumbell in the back of the block. I did turn it over a good bit before starting it up to try to get oil pressure, but I dont think that would have done any damage. Im about to put a new oil pump and o ring in, but im doubting anything will change since I didn't really find anything wrong. Any ideas?

[nathanWS6]

your OPSU is probably bad or broken..

[pajeff02]

Welcome to the site!

What is your gauge setup and how is it wired?

[Ls1wrx]

Its a Autometer cobalt electric gauge, but the oil isn't even reaching the sending unit. I've taken the adapters out of the port, and the oil film stops about half way up them. I guess it was just air pressure making it read 25.

[2002ssslp]

I think it is the OPSU. hook up a mechanical gauge and see what you reading is. They are more accurate then electronis gauges.

[Ls1wrx]

But oil isn't even coming out of the oil port...

[2002ssslp]

But oil isn't even coming out of the oil port...

You have a blockage somewhere in the block. I do not know what to advise except for disasembly of the engine and hot tanking the block and heads. If there is another way to cure this problem I would love to hear it.

[pajeff02]

Start by dropping the oil pan and checking the pickup tube for damage or debris. I can't imagine that you would have an internal oil passage clogged.

[Knight]

+1 with Jeff.

[0rion]

most of the time these pressure problems end up being an o-ring issue....are you sure that o-ring wasn't damaged at all? It doesn't take much. How ovaled was it?

[Smittro]

Things like this are why I keep kits like this around:


I also keep snap ring kits, spring kits, cotter key kits and so forth on hand.

Cheap insurrance imho. If o-rings or fasteners look questionable replace it.

[Firebirdjones]

I lean towards an o-ring fixing the problem.

[Ls1wrx]

It was ovaled enough that there wasn't any resistance sliding the tube into the pump. I put a new pump and o ring in...im not sure if either actually did anything, but atleast I know the o ring is good now. I ended up taking the plugs out and cranking the engine a good bit and finally got pressure. I'll put the rest back together tomorrow and fire it up and hopefully see double the psi as what i did by cranking it.

I've read threads and some people said the pump cant prime and build pressure by just cranking it. Well heres proof that it can.

[0rion]

I don't remember what psi I saw from cranking it with the plugs out.....that's been a bunch of years ago but that's how I did it after the heads/cam. I want to say it went north of 60psi but that's been a while ago. Do you know anything about the motor you're using? How it was treated prior to you having it or if it had any issues? What oil are you using in it? I guess you could fire it up and see what happens......I've known people that have just had low pressure and ran for years without any issue. My buddies vette idles ~25psi but gets up to 40 when he's driving it and has been that way for 5 years. 25 is safe if you go by the 10psi for every 1000rpm rule but it would personally scare me a little if I were seeing that low.

[Ls1wrx]

I dont know anything about the motor, I just bought it from a shop. I put 5w 30 in it with a wix filter. I wouldn't expect 60psi from just cranking it as its only turning 100-200 rpms? Vs. 800 idling but anythings possible. It was on the mark inbetween 25 and 50 but im sure the starter had worn the battery some from when i first got pressure. The battery doesn't have a full charge.

[0rion]

like I say....it's been years since I did mine so I don't remember what it jumped too. I know it took several revolutions and then shot up there. Maybe it was 40?? I barely remember yesterday haha

Good luck with it and hopefully you'll fire that thing up and the pressure will jump up there. Post back and let me know how it goes.

[Ls1wrx]

Fired it up for a few seconds and it jumped up to around 45-50psi. Hopefully it wont drop much once its at operating temp.

[0rion]

is that an oem pump you put back in there or a ported pump? Doing the work anyhow a ported pump would've been the way to go.

[2002ssslp]

Glad you got the problem fixed. Post some pics of the car when it is on the road.

[Ls1wrx]

Got the car up to temp today and and took it for a test drive. Going down the road, psi is around 35, and idle is 25 or a hair under. Idk what the rpms were though, I haven't hooked my tach or speed up yet. On the positive side my coolant stays at 200. Seems acceptable right? Could I put some sort of additive or slightly thicker oil to help? Cold startup is 50psi.