I got an Osiris tune today, and I ended up having problems with what we think is my cats. The guy set my tune back to the factory, but with an 8100 rpm redline. I hit the redline on the way home, and now my oil pressure at idle is 14-15 psi, when before that one time I hit the redline it was 30-31 psi. They hit the redline over and over on the dyno, and I only hit it once while I was driving. The car was up to operating temp, I was in first gear, my car is all the way full of oil, I'm using mobil1 0w40, my car has approx 43000 miles, no ecu codes. What gives?

 

Oil is hot,you lose pressure with added heat.

 

Alright. Ill report back tomorrow morning after I drive it again

 

I just checked the oil and it was cool enough to touch, yet it is still low. Im afraid of it being the oil pump, but after researching thats kind of what it looks like because of the higher redline. Is it possible that the lower oil pressure was set by the tune?

 

Nope. Oil pressure is determinate by bearing clearances and all those tiny oil passages.
What engine, HR or DE? Stock?

 

Hr, takeda dual intakes, megan drift spec exhaust, and the tune with the adjusted afr and redline

 

I would suggest an oil change. While doing that examine old oil. If you can see metallic particles, then your crank bearings are probably shoot.

 

Make sure your oil is not excessively low. Where is it on the dip stick, how far between H and L, or is it not even determinable (below L)? 8100rpm? Are you making power that high even? Seems pushing it unless you are built even for an HR. Engine life will decrease with higher rpm usage. If oil is low, and you start having to add oil, immediately get a compression/ leak down test. Who was this tuner? What shop? Low oil px at idle like you describe sounds bad. Hope that tuner didn't fk you. Also how many miles on the engine?

 

Is there any possibility that the oil pump is starting to fail?

 

That's a possibility too. 8100rpm is starting to get up there, but then again other people rev to 8k...

 

They have me the extra 500 rpm just so I have room to work with. The guy has been doing nissans for 17 years so he knows what he's doing. The engine has 43000 miles on it

 

Oh and the engine oil is at h

 

Really? That seems like much for an engine with such low mileage

 

I drive it this morning and it was the same as last night. It was def cold so it wasn't matter of engine temp

 

Failed oil pressure sender?

 

I've had this same issue for nearly a year. Did oil change, replace oil sending unit also. Before I drive her I always check the dipstick and it always reads "H". I'm thinking its probably a problem with the oil gauge itself...

 

So you did an oil change and that fixed it? I emailed the shop and that's what they said it sounded like from the email. I'm going back over there today so they can take a look.

 

The place said it is probably the sender. Which makes sense because it says I have like <5 psi at idle and still sounds/drives normal. Do you have to drain the oil to replace the sender? And are too many oil changes in a short period of time bad for your engine? I dont want to change my oil for the third third time in 2000 miles unless I have to

 

What page in the service manual goes over how to replace the pressure sender? People keep mentioning that page but I cant find it