FZJ80 High oil pressure at idle (1 Viewer)

[hachimaru]

I've searched countless threads on abnormal oil press at idle, and only find ones about LOW pressure. My issue is higher pressure at idle (+10 psi over)

I recently refreshed the plenum and some other parts. Prior to replacing anything my idle was at 16-19 psi at idle (700~ rpm) depending on weather, which as far as i know thats healthy. It had a bunch of rotten vaccum lines and a grimey TB so i decided to change everything with new OEM stuff.
Now i'm getting 30 psi at 600 rpm, and 60-70 psi at 3000 rpm. Does anyone know why the idle psi is so high? The on throttle pressure is about the same as before i refreshed everything, but the 30 Psi at warm idle is concerning me that theres some compression blow by or something, however i didn't change anything related to any oiling. I'm reading the pressure with a prosport EVO2 oil pressure gauge, with the matching sending unit /harness which came with the gauge.

Am i over thinking this? Did the leaky vaccum lines, bad spark plug gaskets and old pcv valve really cause such a leak in oil pressure? As far as i know 30 psi is not normal for a later model 1fz-fe.


1995 JDM VX 1fz-fe
237000 KM (150k mi)
no engine mods besides oil press gauge and vaccum gauge

Things i replaced:
(All OEM Toyota parts)
every vaccum line
fuel vsv / egr vsv
Intake plenum top two gaskets
TB gasket and cleaned TB
EGR Gasket and cleaned EGR pathways in plenum
Spark plug gaskets (mine were rotted)
Valve cover gasket
new PCV valve and grommet
Distrubutor O ring
coolant bypass hose #1 / #2
new spark plug wires


Thanks in advance

 

[richardlillard1]

The 1fz is spec’d at idle to “4.3psi or more”. No high end of the spectrum is defined. Your numbers for 3,000 rpm are at the high end of the factory spec for that rpm so if it doesn’t smell like oil and runs fine, I wouldn’t worry about it.

 

[Kernal]

What oil/weight were/are you running before and after the work and did you change the oil filter brand at the same time?

 

[hachimaru]

What oil/weight were/are you running before and after the work and did you change the oil filter brand at the same time?

I run shell rotella diesel 15-40 year round. oil filter and oil was not changed before or after working on it. i regularly glance at my gauge and i was always idling at 19 psi almost dead nuts steady

I feel like the new pcv one way valve could be the issue, maybe not letting enough pressure pass through, the ball inside the valve did not seem sticky or jammed when i installed it.

 

[hachimaru]

I’ve ran the engine with the pcv unplugged to see if maybe it would lower my pressure and that had no effect. Also unplugged the exhaust cam breather as if it would make any difference. It still stays pegged at 29-30 with everything warmed up, and after repairing my vacuum leaks I’m seeing a better vacuum than I had marked as a baseline when I first put a vaccum gauge in

I feel like I’m being paranoid but a spike in 10 psi makes me worry.

 

[flintknapper]

You're fine. I run the same oil and have similar pressures.

You might change your oil filter just for peace of mind (use a good quality filter).

But your pressures at highway speed are consistent with mine and my 'idle' pressure (depending on temperature) is between 25-33 psi.

Oil Pressure on Left, Trans Temp on right:

 

[hachimaru]

You're fine. I run the same oil and have similar pressures.

You might change your oil filter just for peace of mind (use a good quality filter).

But your pressures at highway speed are consistent with mine and my 'idle' pressure (depending on temperature) is between 25-33 psi.

View attachment 2625782

Oil Pressure on Left, Trans Temp on right:

Well this makes me feel a little better. I guess my crank case leaks really played that big of a part. Thank you

 

[TexasJack]

My Oil pressure is pegged at the top of the gauge most of the time. It has been since about 2012 when I had the head gasket replaced. I have never smelled oil and it doesn't appear to be hurting anything. I think maybe one of the sensors is worn out. I have done some really long drives with it like this ..... not a problem. I will try to get a pic to post up tomorrow.