what should my oil pressure be
 

out of curiosity what should my oil pressure be at idle?

car is a 2007 sti hawk

closed deck 2.5
mahle pistons (2618)
std rods
new 2.5 crank
high flow oil pump

oil in it is royal purple 10w40

351 bhp, 9k covered so far in engine

getting 1 bar @ idle and between 5-6 under load

Mine is similar, forged 2.5, can reach over 7 bar cold.

I get 6.5 bar under load and about 2bar warm idle forged 2,5

roughly 7-8 bar cold and 2 bar warm idle (bug sti)

6.8-7.5 cold
2-2.5 at temp
Forged EJ257

Havnt you just had your car to chevron ?
Should have asked the Q

Cold idle 6bar
Warm idle 2bar
Under load when at temp 6-7bar

I get 6-7 bar under load 1.6b hot idle after hard drive, 1.8b normal walm temp idle and 5.5 cold idle.

1 bar at idle and i would be aking my turner and a little nervous.

About 6.5 cold start up and 3.0 hot idle. (2.5 forged pistons only) 1.0bar does seem a little low.

since fitting an external oil cooler I'm getting 1.6-2 bar hot idle and 3.3-3.5 on load. Forged 2.1 with 10w50. My readings were higher before deleting the standard modine and going onto a thermostatic plate.

Shrecky , Although this data is not for E257 , I do hope it helps you.


I have just had my EJ20 short rebuilt bei Ashley Wilks.
this is on a Standard crankshaft , std cooler, all new ACL bearings, used heads.
It is not fully on the road yet but I made notes to the oil pressure.


After oil priming by hand in the Cold 10 °C in Workshop with a Supermarket 10W-40 We started up it pegged the oil gauge at idle. After 30-40 min running at 2500 rpm (Fan was on) it was showing >5,5 bar , oil temp 100-105 C , we drained all the oil , new filtered checked the sump magnet. Removed some fine smear particles. Re-oiled with fresh 10W-40 ran another 20 mins, this time to set the rings extending revs to 6000 rpm redrained and checked sump plug , totally clean. (relief ) Idle oil pressure around 1.8 bar.


Re-oiled this time with Fuchs 10W-50 ( Synth ) with Motul additiv (Synth )
ran for another 30 mins. Now the interesting thing is the oil pressure at fully warm fan on ,100-105C oil was now 2.1 bar. I conclude from this that the Fuchs 10W-50 maintains a higher viscosity even at running temperature. No surprise here.


For your case (new crank or not ) If the crank to bearing clearance is toward upper end of tolerance , then you will see the oil pressure drop as things get hotter , a synthetic oil should give you the micro protection on the bearings from cold, and if you choose a higher viscosity Version ( they all vary from manufcaturer even within published range ) then , I would suggest that a synthetic 10W-50 would serve you best now. I doubt that 0,3 bar difference is significant at idle , but when the oil gets to >110C Im pretty certain you need the synthetic micro film to hold up on the bearings is important. I would however shy away from 10-60W I consider this only for full race applications.


Personally I don't see the Point of 5W-xx oils while they have obvious advantage of cold start and drive away they are just expensive to produce and don't really help you once the engine gets really very hot. I drive my Subaru for fun and not to work in Mornings , so it goes out when it has been warmed up.

last time I had oil pressure that low I pulled the pump and found the bolts loose in the back

Lets hope he does not have to go through this again.

Yep, a known problem on the EJ engine. Locking fluid helps (get it done when the cambelt needs changing, for example).