Sr20 high oil pressure (120psi)

[BSPerformance]

I just swapped a new OEM oil pump & used t25 turbo on my sr20det and now once the car warms up I am getting 32 psi oil pressure at idle and up to 120 in higher revs. (Car had no abnormal oil pressure issues befor)
Is Possible I got a bad oil pump with a bad oil pressure relief valve?
Or am I over looking something else I could have done wrong?


EDIT: Things I've tried

I have tried a new sensor for my gauge off my buddies car(1 month old defi's) and it read the exact same as my sensor did.


I have tried to switch from 15w40 to 5w30 oil and no change in pressure

[Primo's Silvia]

Wat type of oil are u running? Weight does affect it slightly? But 120 does seem like ,alot is tht when your on the freeway?

[BSPerformance]

Originally Posted by Primo's Silvia

Wat type of oil are u running? Weight does affect it slightly? But 120 does seem like ,alot is tht when your on the freeway?

Same that I always run, rotella 15w40, never had issues with it befor. It'll go to 120 just by holding the revs up and while driving.

[No 240.. No id]

A lot of times are a oil pressure guage issue. Try to tap and and see if it goes down. My 350z had that oil pressure guage sticking up all the time and so to thousands of other 350z's. Try to tap it a bit and see if it goes down. Good luck.

[wangan_cruiser]

Tap it?

Msgs lngth

[cotbu]

120psi is the max you want to see from oil pressure usually, hard driving what have you.
If you built this engine, and you documented the clearances you should be able to calculate the working oil pressure, and choose the correct oil. Anyway...If you have a tight clearance, you need a less viscous oil, same flow from the pump, less pressure, more power.

10psi for every 1krpm is a good rule of thumb.

[BSPerformance]

^its a stock short block never replaced or touched the bearings/rods/pistons running the same oil(rotella 15w40)and filter(k&n)combo that I was running befor I swapped the pump and turbo.

Originally Posted by wangan_cruiser

Tap it?

Msgs lngth

Yes I did try tapping where oil pressure release valve is while it was running and it had no change.

I'm gonna try a new oil pressure sender and see if it still reads the same

[No 240.. No id]

Originally Posted by BSPerformance

^its a stock short block never replaced or touched the bearings/rods/pistons running the same oil(rotella 15w40)and filter(k&n)combo that I was running befor I swapped the pump and turbo.


Yes I did try tapping where oil pressure release valve is while it was running and it had no change.

I'm gonna try a new oil pressure sender and see if it still reads the same

I ment the gauge it self.. Tap it/ shake it and see.

[Banana_Cute]

maybe a bad oil sending unit?? I have an Xterra thats constantly on "H" all the time. Just gotta change the unit.

[BSPerformance]

tried a new sensor for my gauge off my buddies car and it read the exact same as with my sensor.

and idle

[Davidna2fi]

Drain oil and run 5w20 and see if pressure stays the same. That's really high pressures for sure. Idle should be 10Psi. Where is the oil pressure feed for the gauge?

[jr_ss]

Switch your oil to the T6 5w-40 from Rotella. There's no reason to be running 15w-40, especially in Philly.

[R@ddy]

Originally Posted by Davidna2fi

Drain oil and run 5w20 and see if pressure stays the same. That's really high pressures for sure. Idle should be 10Psi. Where is the oil pressure feed for the gauge?

Are you out of your mind? Idle pressure should NOT be 10psi.
Idle pressure is fine as is, however not in the higher rpm. Oil weight shouldn't affect it that much. I believe my stock SR20 Was at around 90psi at like 7500 rpm with 10w40

[jr_ss]

Originally Posted by R@ddy

Are you out of your mind? Idle pressure should NOT be 10psi.
Idle pressure is fine as is, however not in the higher rpm. Oil weight shouldn't affect it that much. I believe my stock SR20 Was at around 90psi at like 7500 rpm with 10w40

Oil viscosity(weight) will have a huge effect on what pressures he sees.

What oil pump did you replace yours with OP?

[ultimateirving]

15w is pretty thick man. I don't even run that in Phoenix in the summer. Been using t6 5w as previously mentioned for years now. Try something thinner

[Croustibat]

Originally Posted by Davidna2fi

Idle should be 10Psi.

Absolutely not. The strict minimum nissan recommends is 11psi when hot at idle.

Nissan also gives a maximum oil pressure when hot, and that is not 120 psi either ... i think it is between 60 and 70. Can't remember, but that is written in the FSM.

@OP DO NOT RUN 15wxx oil in your engine. 10w is the max, unless you live in the desert.

Basically, you should have between 15 and 30psi at idle, and around 60 at 4000rpm.

I think you have a mix of 3 problems.
The first is a blocked pressure relief valve.
The second is the wrong oil (i don't care what stupid guys tell, these engine don't need 15w oil, just read the FSM people)
The third is a problem with your sensor or gauge. If you were actually running with 120psi oil pressure, these is a very strong possibility the oil filter would have already blown.

[BSPerformance]

It's not the oil, I changed the oil to 5w30 and zero change in oil pressure.
It's not the sensor I tried another one already same exact readings.
The pump was replaced with a new oem timing cover/pump.

[Croustibat]

The sensor converts the pressure in an electrical signal. The gauge processes that signal and then sends commands to move the needle. It is not a direct signal -> move needle thing, only the crappiest chinese gauges do that, and the result is that values change based on electrical system load and parasits ( easily seen on temperature gauges ... set high beams and watch your temps drop 10°C )
If the gauge is faulty and does not process that signal correctly, it shows bad data. If the wiring is somewhat busted or has added resistor due to a bad connexion it can do the same.

32psi at idle is high for a 5w oil, but quite normal with a healthy pump and a 15w oil. If the pressure really did not change, this might indicate a faulty gauge. If it did go lower when switching from 15 to 5w, then i am afraid it is more an oil regulator problem. It just is a ball, pressed on a cone by a spring, most of the time when they fail, they fail open, not closed. Unless it was badly manufactured and the hole leading there was not done, which could have happened too but... i doubt it.

The easiest to check is to use another identical gauge and wiring (or another pressure/gauge combo... not all sensors are the same). I'd start with that. You could check the voltages for the gauge too, maybe it is just that. Gauges can do funky stuff when they get 5V (wiring problem) or 17V (regulator in alternator problem), as the signal coming from the sensor is compared to a reference the gauge gets from that.

Somehow i don't think the wiring is at fault, but it is an easy check so it may be worth it.

If the oil pressure regulator is stuck, the oil filter is taking a serious beating, and so are all oil gaskets. If you can't see any oil spilling around, maybe you are lucky and it just is a faulty gauge.

My money is first on that TBH (or, if there is a central unit where the sender connects, like on older defi systems, that central unit), so that may be not much to fix.

If it really is not though, it means either something is completely clogged, or the oil pressure regulator is stuck. Either way, that is really bad, so until you are absolutely sure this is not an actual oiling system problem, run that engine the strict minimum.

[BSPerformance]

It dropped to 28psi at idle but still spiking just over 120psi.
I tried another gauge and was getting the same readings as my gauge.
Going to swap out the wiring next and see if that switches anything.

[R@ddy]

Change that thick ass oil!!!

[homeslicej2]

According to FSM, after the engine is warmed up to normal operating temp, it should have no load (revving in neutral) oil pressures of:
more than 11psi at idle
Engine speed at 3200rpm 46-57psi (again in neutral, not while driving)
I would get (buy/rent) a decent mechanical check gauge, drive the car until it's at operating temp, disconnect the DEFI sensor (which should get its reading from the stock dummy light location next to the oil filter), connect the mech check gauge (don't burn yourself), and then start it up to check at idle and have friend help you check at 3200rpm. If it's still high, and this only happened after the new pump and used turbo, then either you installed something incorrectly, have a blockage somewhere, or defective parts.

[Croustibat]

Not 100% sure but i think on a CA18DET and an SR20DET, the turbo has a parallel oiling system. Even if it was blocked, it should not make pressure go that high.

It really looks like a faulty oil pump pressure regulator now, sorry man