Subaru Impreza GC8 & RS Forum & Community banner
1 - 10 of 10 Posts

·
Registered
Joined
·
422 Posts
Discussion Starter · #1 ·
Well I was driving around the other day and noticed that my oil pressure gauge was reading very very low - at idle is reads 0.... but the engine sounds alright, no knocking, no abnormal/unusual ticking. Then at WOT, it slowly rises to 20psi. This was done all with the engine warm as I noticed it once I was on the highway for a good 30minutes.

I started it up this morning and at cold idle it is only 40-60psi max. I read that it should be higher when cold. I did not drive it today as I do not wish to hurt the new engine.

It has a new sti oil pump, and all new seals/gaskets. This is on my ej257 engine. There are no leaks anywhere. My oil pressure gauge is one from advance auto - sunpro I believe. It has the copper line going to it and I have it tapped on the back of the block, passenger side.

Could my pick-up tube be clogged ? I cleaned it out when I built the engine, so I do not think its that. Any ideas/suggestions to try? I am open to anything. I do not have another oil pressure gauge to test - this one seemed to be working fine, and its only 5months old (give or take a month).

Please - any suggestions? I will be pulling the engine out to check the oil pan, and pickup friday night - but would like other suggestions, that can easily be done in a day while I have the engine out.
 

·
Premium Member
overdeveloped beater
Joined
·
8,335 Posts
check for a leak at the connections. They aren't of the best quality....and you only get one good shot at making them seal.
 

·
Registered
2015 WRX
Joined
·
2,350 Posts
If you have zero oil pressure the oil pressure light in your cluster will come on. It sounds like from your description there is a clog somewhere in your feed line to the gauge or the gauge itself is broken. The oil pressure should change very rapidly.

I'm in VT and have a spare autometer gauge... I dropped it a while ago so it reads 20 psi off, but the needle actuates as it should... if you're interested in using it for testing let me know.
 

·
Registered
Joined
·
422 Posts
Discussion Starter · #4 ·
hey suby25 ... yeah -- that would be very helpful, like I said ... this has me pretty stumped as the oil light is off, and goes off after like a second of two when first starting - and it stays off while the car is running. Also the copper line is brand new, just bought it sunday and installed it yesterday - it had the plastic stuff ... crap .... so im down to either the gauge or the pickup.

Suby25 -- where abouts in VT are u located ?
 

·
Registered
Joined
·
422 Posts
Discussion Starter · #5 ·
also --- when the gauge pressure changes, its not a fast change, but it moves slower then i would think -- like it doesnt spike right up to the pressure. and on the throttle it doesnt really move once its warmed up.
 

·
Registered
2015 WRX
Joined
·
2,350 Posts
Replied to your PM.

My oil pressure gauge changes pressure very rapidly. It will rise from 30 psi at idle to 60 psi just with a blip of the throttle.

Did you use teflon tape on any of the fittings? Perhaps a piece is lodged in the oil feed line somewhere?
 

·
Registered
Joined
·
422 Posts
Discussion Starter · #7 ·
no, I used some pipe dope stuff that I use at work - propane technician. I checked the oil passages and they seem fine where I tapped for the oil pressure gauge. I am gonna take the oil pan and the oil pump off this weekend. Maybe some of the RTV got stuck somewhere - or maybe the pan isnt sealed good (altho I did use a good amount of sealant).
 

·
Registered
'97 Emerald Green GF4 5spd
Joined
·
271 Posts
Hey Vipergtrdj, Im not sure if this info is any useful but when at cold start, I notice that my Oil Pressure is always at 80 PSI then as it gradually get warmer it would drop to until when at normal operating temp. it fluctuates between 15-20psi.. From my understanding that anything below 10PSI is bad.

GL
 

·
Registered
Joined
·
422 Posts
Discussion Starter · #9 ·
yeah, I am gonna pull the oil pan off and check the screen on the pickup tube. I am also going to pull the oil pump and check the o-ring gasket that is on the back of it, maybe it got messed up when putting it on.

I changed the gauge and it reads about 10psi at idle, and it is around 40-50psi when on the gas. Still not that high, but better then the other gauge was reading.
 

·
Registered
2015 WRX
Joined
·
2,350 Posts
Is this a turbo motor, or just a 257 shortblock with NA heads?

FWIW on my EJ20G, I see 90 psi at idle from cold startup, 95-100 psi while cruising while oil is cold. Once the car is up to temp, 80 psi during cruising and 30 psi at idle. I would expect lower oil pressures for NA motors.

A friend of mine rebuilt his 257 and forgot the o ring gasket on the oil pump and blew his motor on the dyno. Air was getting sucked in and mixed with the oil and he spun a bearing due to low oil pressure. I guess, as you mentioned, that could be causing your problem.

Good luck figuring it out, hopefully no damage was caused.
 
1 - 10 of 10 Posts
Top